GENERAL WORK PLACE SAFETY RULES

1.0 Purpose
The company’s and government’s Primary objectives are to ensure the safety and health of the Employees, and to protect property.

1.1 Safety Rules have been developed with input from Supervisors and Employees. While held to a minimum, the rules address behaviors and work practices that can lead to accidents and injuries.

1.2 Each Employees should become familiar with and follow General and Departmental Safety Rules. Supervisors must enforce Safe Work practices through strict adherence to Safety Rules.

1.3 Most accidents can be prevented if everyone uses assigned safety equipment and follows the established safety rules. To operate a safe and successful business, we must work as a team to:

“THINK SAFE, WORK SAFE, AND BE SAFE”

2.0 Communication of Safety Rules
Communication of safety rules is accomplished by:

• Discussion during New Hire Orientation
• Published in the New Hire Orientation / Company Handbook
• Posting throughout the facility
• Annual refresher training
• On-the-spot corrections and reinforcement by supervisors

3.0 Additional Operating Safety Rules
The Company has additional safety rules for specific operations and departments that apply to those engaged in hazardous work areas or operations. Examples of these rules are contained in other safety manual chapters and standard operating procedures such as those for:
• Lockout-Tagout
• Confined Space Entry
• Welding Safety
• Forklift Safety

4.0 Posting of General Safety Rules
General Safety Rules will be posted in conspicuous areas at all locations.

5.0 GENERAL SAFETY RULES

5.1 Report all work injuries and illnesses immediately.
5.2 Report all Unsafe Acts or Unsafe Conditions to your Supervisor.
5.3 Use seat belts when on Company business in any vehicles.
5.4 Firearms, weapons, or explosives are not permitted on Company Property.
5.6 Use, possession, sale or being under the influence of illegal drugs, misuse of prescription drugs and/or alcohol is not permitted on Company Property or while “on duty”.
5.7 Only authorized and trained Employees may repair or adjust machinery and equipment. Lock and Tag Out Procedures must be followed before removing any machine guards or working on powered machinery and equipment. Re-place/fix all guards when the job is completed.
5.8 Only qualified and trained Employees may work on or near Exposed Energized Electrical Parts or Electrical Equipment. Follow Electrical Safety Rules when working with electrically powered machinery and equipment.
5.9 Only authorized and trained Employees may enter a posted Confined Space. All confined spaces will be posted Confined Space – Permit Required. Entry is allowed only after permits are properly issued.
5.10 Only authorized and trained Employees may dispense or use chemicals. It is your responsibility to know where SDS’s (Safety Data Sheets) are located and that they are available for your use and review.
5.11 Keep work areas clean and aisles clear. Do not block emergency equipment or exits.
5.12 Wear and use the prescribed Personal Protective Safety Equipment. This includes foot protection, head protection, gloves, etc.
5.13 Smoking is permitted only in the designated “Smoking Areas”.

6.0 Store combustible materials properly
When not stored properly, these combustible materials are serious fire hazards. They can put everyone’s safety at risk. Make sure these materials are stored in areas with proper ventilation.
6.1 Any spills made while working with these sorts of materials should be properly cleaned right away.

6.2 Every workplace that handles flammable and combustible materials needs to do so in accordance with Workplace Health and Safety rules and regulations, depending on the state in which the business resides.

6.3 All materials need to be properly labelled, based on GHS – the globally harmonised system for the classification and labelling of chemicals.
GHS defines a flammable liquid as a liquid having a flash point of no more than 93°C. The chemicals are further classified according to their flash points.

7.0 The person who runs the business is responsible for the following:
7.1 Creating and conducting all emergency planning.
7.2 Ensuring everyone on site has personal protective equipment.
7.3 Dealing with risks from flammable solvent vapors, including the places where it exceeds 5% of the lower explosive limit.
7.4 Managing fire and explosion risks.
7.5 Keeping the amount of flammable and combustible substances at the lowest practicable quantity.
7.6 Providing a manifest and site plan if there is too much of one substance on site.
7.7 Ensuring storage areas are properly labelled and signs are visible
Containing and managing leaks and spills.
7.8 Making sure containers, pipework and attachments are damage-free.
7.9 Providing appropriate fire protection systems.
7.10 Managing all risks associated with storage and handling systems and equipment.

8.0. Training of employees
8.1 Ensure proper training when handling equipment or machinery.
Any employee tasked to handle tools, equipment, or machines should go through proper training first. Anyone who isn’t trained should never be assigned to handle heavy machinery and should stay away from it.
8.2 Training is not enough for high risk work involving heavy equipment and machinery.

9.0 Appropriate Licences to work
9.1 Workers need to have appropriate licences to work in certain conditions and handle certain machinery and/or equipment. Once acquired, this licence needs to be renewed when stated.
9.2 The licence is categorized and you need to make sure your employees are eligible for the category your business needs.
9.3 A Licence to Perform High Risk Work is for handling different machinery and equipment such as:
— Cranes
— Reach stackers
— Elevating platforms
— Hoists
— Boilers
— Scaffolds
9.4 You need to have proper First Aid Kits and trained personnel who can administer it properly.

10.0 Proper clothes appropriate for tasks.
10.1 Employees who will be using power tools should wear proper workwear when operating machinery. Have them wear the right shoes and protective equipment for the task. Only use gloves that fit right and that are appropriate for the task.
10.2 Different industries require different uniforms and protective gear.
For example, medical personnel need uniforms that will prevent them from being contaminated with bacteria while enabling them to move comfortably.
10.3 Industrial workwear needs to provide UV protection, protection from fire and other hazards. Of course, it all depends on the industry. Naturally, you will opt for sturdier fabrics if you need to equip workers in the automotive industry. On the other hand, those that work with open fire and flames need fire retardant fabrics.
10.4 Food processing garments don’t have to be that special, but they need to be made from antibacterial fabrics to prevent bacteria contamination.

11.0 Clearly label designated hazardous zones
Areas, where dangerous equipment is stored should be clearly labelled and the walkways should be highlighted with the necessary signage.
11.1 The Sign Shed General warning signs
It also helps to mark the hazardous zones with tape or black and white stripes painted on the floor. This keeps employees aware of dangerous surroundings and helps them avoid accidents that may cause serious injuries.
11.2 It’s important to make sure the signs are properly made and positioned.
Regulatory signs warn about actions and measurements required by law. They are subdivided as follows:
a. Prohibition signs
b. Mandatory signs
c. Limitation or restriction signs
11.3 Hazard signs that warn about dangers and hazards. They are subdivided as follows:
a. Danger signs – warning of a particular hazard that can be life-threatening.
b. Warning signs – warning of a hazard that is not likely to be life-threatening.
11.4 Emergency information signs include directions to emergency-related facilities such as exits, safety equipment or first aid facilities, including fire signs.
11.5 Free Danger Signs
Free Caution Signs
Free Mandatory Signs

12.0 Provide first aid training
Providing employees with first aid stations goes a long way towards safety and is a practical way to deal with emergencies. These wall-mounted stations must be fully stocked with a first aid kit that has all the medicines and supplies needed to handle the most commonly encountered situations in the industry/office.

13.0 Fire Protection system
13.1 Fire protection systems include fire suppression, sprinklers, smoke detectors, and other fire protection equipment that works in tandem to protect against fire should be in place and in perfect working condition.
13.2 Proper training of employees/fire fighting team in operating/testing of fire protection system. Regular checking and keeping the fire protection system in perfect working condition. Frequent fire drill to be undertaken to keep employees ready to face fire emergency.
13.3 It is best to work with a fire protection company that understands the needs of your property/industry and provides a variety of integrated protection systems.

14.0 The first step toward creating a safer workplace is to undertake a professional workplace risk assessment. This will identify all the potential risks that lurk in your workplace. Once that is done, you can go on and take all the necessary precautions.

BOILER HYDRAULIC TEST

  • Leakages in the boiler pressure parts (Tubes, headers and Pipes).
  • To test the soundness of welded joints and associated pressure parts of the boiler in order to comply the code requirements.
  • To prove the strength of the boiler pressure parts at a pressure greater than the working pressure of the boiler at ambient temperature.

The hydraulic test of the boiler is carried out at the following conditions situations.

  • On completion of the boiler erection activities
  • On completion of repair work on boiler pressure parts
  • On completion of annual overhaul
  • At the request of statutory authority to fulfill the statutory requirements.

2.0 Preparation for Boiler Hydraulic test:

The following activities have to be completed before carrying out the boiler hydraulic test.

• Ensure that the complete boiler Pressure part erection is completed.

• Ensure that all welding/NDT and heat treatment activities are completed.

• Ensure that necessary pressure parts welding are completed as per the drawing.

• Ensure that pressure parts welding joints are free from paint & rust

• Ensure that, all the buck stays, its guides and anchors are installed as per the drawings. (Check and confirm the clearance provided in the guides and anchors are strictly as per the drawing).

• Ensure that all the boiler permanent supports, structural bracings are provided as per the drawings.

• Ensure that all temporary supports provided for erection supports are removed.

• Ensure that, all tools; equipment and loose items have been removed from the drums and manifolds.

• Ensure that, steam drum, man holes and manifolds inspection caps are properly joined and tightly sealed.

• Ensure that, the constant load hangers are locked in position with locking pin and the spring loaded hangers are locked.

• Ensure that the Boiler filling arrangements are ready.

• Ensure that Hydraulic testing pump is available.

• Ensure that Power supply to the pressure raising pump should be available.

• Ensure the DM water quality & availability as per requirement. (Minimum three (3) times of the boiler water holding capacity shall be readily available).

• Ensure that, minimum two set of spare gaskets for the drum and boiler important gaskets must be available ready.

• Ensure that proper lighting, approach platforms and communication systems, are ready.

• Ensure that, the following temporary arrangements are completed for conducting a hydraulic test.

• Temporary piping connection from pressure pump discharge to hydro test connection point in the Boiler.

• Boiler filling line to be made ready from existing DM fill pump station for Boiler filling.

• Ensure that, all the temporary piping’s are adequately supported.

• Ensure that minimum three (3) numbers of calibrated pressure gauges are fitted at the identified locations (One in the steam drum, one in the steam outlet header and the other at the outlet of the hydraulic pump).

• Ensure that, the dial pressure gauge used in the testing shall have dials graduated over the entire range of the hydro test pressure.

• It is preferable to have calibrated pressure gauge size greater than 200mm.

• Ensure proper and adequate man power is available during the test.

• Ensure that, the drum internals are not fitted inside the steam drum.

3.0 Boiler Filling Operation for Hydraulic testing

3.1 Ensure that the following valves are closed.

• Root valves of all instruments.
• Chemical dosing line valves
• CBD and IBD Valves
• All header and pipe drain valves
• Soot blowing system and sample cooler system isolation valves.

3.2  Ensure that, the following valves are opened.

• Hydro test connection valve
• Filling line valve
• Drum vent valve
• Hydro test pressure indicator isolating valves
• Super heater vent valve

3.3  Ensure that, the following DM water quality is maintained.

• PH between 8.5- 10.5.
• The water quality shall be as per contract with supplier.
• DM water temperature should be maintained between minimum 21 °C to maximum 50°C.
• The DM water and the metal temperature of the pressure parts should be above the ambient air dew point to prevent condensate formation on the pressure parts being tested, which interfaces with the detection of small leaks.
• Open the filling line valve and start filling the boiler through low point drains.
• Continue the filling until the water starts coming out through all the air vents of boiler drum and super heater headers. Ensure air is released completely.
• Do not weld any pressure parts or attachments to the pressure parts, with water inside tubes.
• Once the boiler is completely filled, close all the air vents, when water starts coming out freely without air bubbles, and stop the filling pump and isolate the filling pump from the boiler.

3.4 Carry out inspection in the designated areas. If leaks are observed at this stage, the water level must be lowered on Boiler and emptied as necessary to attend the leakages. After attending the leakage’s the procedure for filling the boiler shall be repeated. Open the hydro test connection isolating valve and put pressure pump on line.

 

4.0 Pressurization and Inspection

If all the condition is satisfactory start the pressurizing pump by keeping the discharge pressure relief valve open and ensure no person inside the furnace. While raising the pressure, the identified test team should go around the boiler for inspection. Once the Boiler pressure is raised to 10 kg/ cm2 (g) stop the pump and observe the pressure drop.

If no leakage is observed to the satisfaction of the inspecting personnel, start the pressurizing pump. Raise the pressure gradually to 25% of the hydro test pressure and repeat the above steps. Similarly do it for 50% and 75% of the hydro test pressure. When the pressure reaches the hydro-test pressure, stop the pressurizing pump and observe the pressure drop for 30 minutes and identified test team should inspect the boiler thoroughly to check for any leakage or sweating. Ensure that the test pressure never exceeds more than 6% of required pressure. If any leakage is identified it is to be attended after draining the water and repeat the hydro test as mentioned above. If no leak is observed release the -boiler; for further work. Reduce the boiler pressure gradually by crack opening drain valves till the boiler is 2 kg/ cm2 (g) and then open all the vent valves.

5.0 Hydraulic testing safety precautions
For pendent type (Non drainable) superheaters, necessary precautions are taken to avoid corrosion. DM water with oxygen scavenger added to 300ppm and PH not more than 9.5 to be used. This may then be left filled after the test. In case of welded safety valves, remove the hydro test plug and re-install the normal safety valve seat, after de-pressurizing and draining the boiler. In case of flanged safety valves, remove the blind flange and refit the valves. Re-install the instruments that have been sealed off for the test. The drained water shall never be used. Boiler shall always be filled with treated water as specified in the contract. Filling the boiler with un-treated water will cause internal damage and corrosion of pressure parts.

 

SAFETY VALVE FLOATING

PROCEDURE FOR SAFETY VALVE FLOATING

1.0 OBJECTIVE

The objective of this procedure is to outline the general procedures involved in setting of the safety valves to the designed set pressure before allowing the boiler to go for commercial operation. Follow vendor’s manual for adjustment of set pressure.

2.0 PRE-REQUISITES
Ensure proper mounting of the safety valve exhaust pipe, such that no load is coming to the safety valves. Check the drip pan assembly and its drains are as per the requirements. Follow instructions of vendor for safety valve exhaust piping and its support.

3.0 PROCEDURE

3.1 Normally the highest set pressure valve is the valve floated first. While setting this valve other safety valve is gagged. Start the boiler as per cold start up procedure by modulating the firing. When the drum pressure reaches about 75% of operating pressure gently tighten gage on other safety valve. Raise pressure slowly by throttling start up vent valve. When 80% of popping up pressure is reached manually operate the safety valve under test. This will blow off any debris or dust left over in the valve internals.

Raise the boiler pressure by modulating the firing. When the pressure reaches nearer to the set pressure close the start up vent. While the safety valve pops (lift), open the start up vent valve and note down the lifting /set pressure value.
When the valve sits back, note down the reset pressure. Control of drum level is important to avoid possibility of water carry over from drum into the super heater.

The set pressure is adjusted by either tightening or loosening the adjusting nut. Tightening the nut increases the set pressure and vice versa. Blow down which is the difference between set & reset pressure should normally be within 5% of the set pressure. For popping pressure and blow down adjustment proceed as described below:

3.2 Popping pressure adjustment

Before proceeding to check the popping (lift) pressure, the accuracy of the pressure gauges to be used should be ascertained.
To adjust the popping pressure, remove the lifting gear, exposing the adjusting bolt lock nut. Loosen the lock nut if the opening pressure is low tighten (turn clockwise) the adjusting bolt, if it is high loosen (turn counter clockwise) the bolt. When the desired pressure is reached –also after each adjustment –the lock nut should be securely tightened to prevent loosening of the bolt.

Caution: The adjusting bolt should never be turned when the boiler pressure is near the set pressure of the valve. Adjustments should be made when the boiler pressure is at least 10 % below the actual popping pressure of the valve. Unless this precaution is taken, the valve disc may rotate while against the nozzle and damage the seats.

3.3 Blow down adjustment

When the popping (lift) pressure is changed a slight adjustment of the blow down may be required. Raising the popping pressure lengthens the blow down, lowering the popping pressure shortens.

Caution: Never make any ring adjustment when the boiler is under pressure without gagging the valve properly.

If the blow down is not as desired when the set pressure has been obtained, it will be necessary to adjust the rings. The guide (adjusting) ring is the principal blow down control ring. To change its position, remove the guide set screw on the back of the valve body. Insert a screw driver or similar tool and engage one of the notches (these can be seen through set screw hole).The ring can then be turned to the right or left as desired. Turning the guide (upper) ring to the right raises it and reduces the blow down. Turning the guide (upper) ring to the left lowers it and increases the blow down.

After each adjustment always replace and tighten the set screw being careful that its point engages a notch and does not rest on the top of the tooth.

Every safety valve is fitted with a lower or nozzle ring which permits very close adjustment when operating conditions make this desirable. This ring is carefully set before the valve leaves the factory and rarely needs adjustment as its main purpose is to do away with simmer or warn preceding the pop without much effect on the blow down. No attempt should be made to eliminate a short warn.

The nozzle ring is adjusted by removing the set screw and turning the ring with a screw driver. Turning it counter clockwise to the right raises it and increases the popping power and there by eliminates warn. The nozzle should be moved only one notch at a time and the valve action checked after each adjustment.

On high pressure valve the nozzle ring can be very effective in reducing the blow down. To reduce blow down turn the nozzle ring clockwise to the left (lower it) one notch at a time until the valve begins to warn or simmer before popping. When this notch is reached raise the ring one notch. Any further adjustment should be done with the guide (adjusting) ring.

Super heater safety valve should be set and adjusted on steam which is superheated near to the operating temperature. This is essential because the ring settings required for good operation with superheated steam are different from those for saturated steam.
The same procedure shall be followed for floating the other safety valves. While floating a safety valve other safety valve should be gagged.

Note: Boiler reaches the maximum design pressure during safety valve floating hence thermal expansion readings to be noted during this activity.

4.0 SAFETY

• The area around the safety valves and escape pipe should be barricaded and only essential personnel should be in the valve vicinity.
• Access platform to the safety valves as required should built with access and escape paths for emergency purposes.
• High noise level during safety valve floating, therefore ear defenders must be worn by test team personnel.

PROTOCOL FOR SAFETY VALVE
`
Checks prior to safety valve floating

1. Model and style of safety valve :
2. Type of gasket provided at inlet flange :
3. Tightness of flange bolts : Done
4. Exhaust piping & support status : Completed
5. Accessibility & working space near valve :
6. Gags for other safety valves
(Hand tightened only)
7. Hand Popping : Done

SAFETY VALVE FLOATING RESULT.

Valve tag No. SR. No Design Set (Lift) Press Actual Set (Lift) Press Reset Press Blow Down

Result : Accepted /Not accepted.

Remarks :

Signatures

STEAM BLOW OUT

STEAM BLOW OUT

1.0 OBJECTIVE
The purpose of steam blowing is to dislodge scales, remove loose material, iron pieces, weld slag etc., that might have been entrapped inside the piping of Superheaters and other station steam piping during erection. Failure to ensure absolute cleanliness of the steam piping may result in damage to the Turbine blades, Valves etc. The steam blow out operation is carried out after Boiler acid cleaning.

2.0 BASIC – TECHNIQUE
2.1 The steam blow out is carried out by the ‘puffing method’. The dynamic disturbance available in this method will give a thermal shock to the system being purged to dislodge the scale etc., which will be subsequently carried away by the expanding steam.
2.2 For the steam blowing to be effective, the ratio of the kinetic energy at steam blowing conditions to MCR conditions should be greater than one(1).This is determined by what is called the ‘DISTURBANCE FACTOR’ and is calculated by using the following formula :
Disturbance Factor, K = Vb x Fb2/Vm x Fm2

Where,
Vb = Specific volume of the steam at blowing pressure
Fb = Mass flow rate of steam at the blowing pressure
Vm = Specific volume of the steam at Boiler MCR condition
Fm = Mass flow rate of steam at Boiler MCR condition.
Before the steam blowing operation the blowing pressure should be decided/calculated to give the required Disturbance Factor. The pressure normally adopted is 40 Kg/cm2.
2.3 During the blow out operation the cleanliness of the piping is determined by the use and study of ‘ Target Plates’ made of specified material (MS, SS, Aluminum or others) located in an assembly in the steam blow path, in the temporary exhaust piping at a location nearest possible to the permanent pipe work.

3.0 THE SCHEME

The steam blow out operation is carried out in stages to include the maximum possible length of steam piping. In order to achieve effective cleaning, all the station piping is sectionalised and steam blown. Turbine is bypassed during steam blowing . The stages normally followed are;

  • Superheater : The superheater and main steam pipes are are steam blown through to the turbine main steam chests, and from there to atmosphere using temporary pipe work. The turbine steams valve are replaced by temporary blanks.
  • Superheater and reheater :  After superheater steam blowing is complete, the temporary pipe work  is rearranged so that the turbine main steam chest discharge pipe work is replaced with temporary connections to the cold reheat steam pipes,  discharging to atmosphere using the turbine reheat intercept steam chests, and temporary pipe work.

4.0 PREPARATIONS, PRECAUTIONS & CHECKS
4.1 Boiler acid cleaning and passivation operation are satisfactorily completed. All the temporary piping for acid cleaning is removed and permanent pipe connections restored, Drum intervals are fixed and hydro test conducted.
4.2 Main steam and all the station steam piping erection are completed, with all supports and hangers provided as per drawing
4.3 Temporary piping for blow out erected. Temporary blanks installed wherever applicable.
4.4 Temporary blow out piping checked for proper anchoring and safe discharge outside the building. They should be able to withstand the excessive reaction forces of steam blowing. The exhaust area suitably fenced and ‘ CAUTION ‘ notice displayed prominently.
4.5 The diameter of the temporary piping should not be less than the diameter of the respective lines to be steam blown.
4.6 All the permanent and temporary piping included in the scheme of blow out are adequately insulated before commencing the steam blow out operation.
4.7 Electrically operated Temporary blow out valve, if used, should be installed on the Main steam line and its operation checked. For the blow out to be effective these valves be fast acting with an actuation time of about 30 to 40 seconds.
4.8 All Flow nozzles, Strainers, Orifice plates, Control valves and Attemporators are removed and temporary spool pieces fixed in place. NRV flaps should be removed from NRV’s in the steam blowing path.
4.9 Hydrostatic test plugs should be removed and all the safety valves are thoroughly cleaned and assembled.

4.10 The target plate fixing arrangement erected and checked. Sufficient quantity of target plates of the specified material are available.
4.11 Sufficient quantity of DM water available and the DM Plant is in operation.
4.12 The Boiler is ready in all aspects, including, protections, interlocks, instrumentation, chemical dozing etc., for Light up and raising pressure.
4.13 Ensure that no loose debris or other material are left inside permanent or temporary piping.
4.14 Drains going to any Vessel should be left open to atmosphere, preferably outside the TG Hall.
4.15 Before beginning the steam blow out determine/decide on the pressure for the blow out to achieve correct disturbance factor.
5.0 STEAM BLOWING – PROCEDURE
5.1 Boiler is started up, following normal startup procedures. All the normal recommendations and permitted operational limitation should be strictly observed.
5.2 Light up the Boiler and raise the steam pressure slowly as per O & M procedures up to 20 –25 Kg/cm2. Warm up the line by opening the bypass of Boiler steam stop valve and then open the Boiler stop valve. Boiler fires are put off and electrically operated temporary valves are opened and valves are closed at 10 kg/cm2 start up vent to be closed during the above period. During 1st blow, the boiler associate and station piping are completely inspected for any abnormality.
5.3 After inspection, light up the Boiler and raise the pressure to the predetermined value – 40 Kg/cm2, for the first stage of the blow.
5.4 Kill the Boiler fire. Open the electric operated temporary valves EOTVs and give blow till the pressure drops to a specified value, so that the saturation temperature change is limited to a maximum of 40C (This is to prevent undue thermal stresses in the Drum and Headers). Close the EOTVs.
5.5 During steam blowing, the following observations are recorded.
i) Drum level swings.
ii) Steam pressure drop at various sections.
iii) Steam temperature at various sections.
iv) Duration of steam blow.

5.6 After EOTVs are closed at stop steam blowing, boiler is relighted up and conditions are re-established for next blow. The standard practice is to limit the number of blows per day to 6 to 8 at an interval of 1½ hrs. for each blow, with overnight cooling.
5.7 Continue steam blowing until Target Plate is clean (decided by completion criteria– see clause 6.0 ). Use Target Plates after every three (3) or four (4) blows and for every blow in the last stage.
5.8 After First stage completion, prepare for the second stage operation.
5.9 Complete second stage at specified pressure till target plate is clean
5.10 Prepare for the next stage steam blowing.
5.11 Complete all stages of steam blowing one by one.
5.12 Each stage will normally be steam blown at specified pressure.
5.13 After completion of steam blowing remove the temporary piping and blanks, install Flow nozzles, Control valves etc., and reweld piping as per drawing.
6.0 TARGET PLATE ANALYSIS & COMPLETION CRITERIA
The number of impacts found on the Target plates give indication of the pipe cleanliness. The highest velocity of steam is in the centre of the pipe. Hence judgement should be made for the end point of steam blowing in the central zone of the target plate. The piping shall be considered clean if number of impacts on an area of 40mmX40mm:
– No impact with a size > 1mm
– Less than 4 impacts with a size > 0.5mm
– Less than 10 impacts with a size > 0.2mm
However, it is best that such completion criteria be discussed and finalized, before start of the steam blow out operation.

7.0 STEAM BLOWING OF MISC. STEAM LINES
• Steam lines like ; steam headers to various HP, MP and LP consumers are to be steam blown by continuous blowing method. The parameters of steam blowing for these lines will be different and should be strictly followed.
• HP Steam consumers for turbine drives, the line shall be steam blown till the target plates are clear. In other areas steam lines shall be steam blown till the steam quality at outlet is clear.
8.0 SAFETY
8.1 Personnel not in volved in the steam blow operation should be moved away from the area.
8.2 Adequate communication system should be setup to warn personnel when each blow is about to commence and on completion.
8.3 Personnel should be stationed at strategic points and in case of any abormality/emergency situation blow out to be stopped and problem investigated / corrected before commencing steam blow out.
8.4 All personnel in the vicinity of steam blow out must wear ear plug.
8.5 While fixing and removing target plate , the steam supply will be isolated by closing stop valve and its bypass and permit for work will be issued.
9.0 STEAM PARAMETERS FOR STEAM BLOWING
• HHP Steam lines : Pressure / Temperature : 40 kg/cm2/ 400 deg C
• HP Steam lines : Pressure / Temperature : 30 kg/cm2 / 350 deg C
• MP Steam lines : Pressure / Temperature : 10 kg/cm2 / 250 deg C
• LP Steam lines : Pressure / Temperature : 5 kg/cm2 / 250 deg C

9,0 REFERENCES

9.1 VGB Guide line for steam blowing ( VGB-R513e)

PROTOCOL

Site : Job No.
Date :

1. Circuit included :
2. Steam pressure before blowing : bar (g)
3. Steam pressure after blowing : bar (g)
4. Duration of each blow : minutes
5. Time interval between two blows : hrs.
6. Total Nos. of blows : nos.
7. Number of targets checked : nos.
8. Material of targets plate :
9. Condition of final target plate after blowing :

Result
Accepted / Not Accepted

Remarks

Signatures

ALKALI BOIL OUT

PROCEDURE FOR ALKALI BOIL OUT

1.0 OBJECTIVE
The purpose of alkali boil out is to remove from boiler internals the deposits like oil, grease, mill scale etc., resulting out of manufacturing, fabrication and erection procedures. Such deposits in the boiler tube walls severely restrict heat flow across the tube walls resulting failure due to overheating.

2.0 PREREQUISITES

In order to commence alkali boil out of the boiler, following prerequisites/inputs have to be made available:

2.1 Mechanical completion of boiler including auxiliaries and piping.

2.2 Completion of boiler hydro test and other commissioning activities including refractory dry out.

2.3 Readiness of Electrical Equipment, controls and Instrumentation.

2.4 Adequate illumination in and around the boiler house.

2.5 Electrical power for motorized valves, gauge glass illuminator, etc.

2.6 Demineralised water through boiler feed water pumps.

2.7 Readiness of sample collection system.

2.8 Chemicals required for the process.

2.9 Full readiness of Boiler for lighting up and its thermal expansion.

2.10 Water testing facilities including pH and oil detection.

2.11 Readiness of chemical dosing system.

2.12 Inspection and mechanical cleaning.

2.13 Make visual check of the entire boiler unit and remove all debris.

2.14 Remove drum internals (If required) from steam drum as specified by TBW engineer.

2.15 After visual checks, close all access to the boiler unit internals.

2.16 Controls, interlocks and other requirements

Following minimum controls and requirements are necessary for boiler operation.

2.17 Good working Drum level gauge glass with illuminator assembly.

2.18 Boiler drum pressure gauge.

2.19 Safety/relief valves with gags or hydrostatic plugs removed.

2.20 CBD and all drain valves in good working order.

2.21 Water level control and associated alarms.

2.22 Cooling water/air piping.

2.23 Furnace pressure gauge.

2.24 Temp.indications for bed, flue gas, feed water and steam line.

2.25 Safety interlocks.

During alkali boil out, transmitters connected to steam piping and steam drum will be kept isolated to avoid any damages to transmitters due to alkali.

 

3.0 PROCEDURES

3.1 Ensure that blow down and drain connections are terminated to safe location.

3.2 Ensure that all dampers are in good working condition and “OPEN” “CLOSE” positions are marked correctly.

3.3 Ensure that the feed water pumps operate satisfactorily.

3.4 Fill specified quality feed water to NWL by keeping all vents open. Drain the water completely through bottom drain, keeping the header outlet valve fully open. With this the boiler gets rinsed.

3.5 Fill the unit with specified quality of water up to the drum level approximately 200 to 300mm below the man hole opening. (Fill the drum through normal feed water connections). DM Water should be used for boil out operation. Add some hydrazine in Deaerator storage tank to have 1/2 PPM of hydrazine traces in boiler water.
3.6 For alkali boil, 2500ppm of hydrous tri sodium phosphate (Na3PO4 12H20), 1000ppm anhydrous di sodium phosphate (Na2PO4) and 225ppm wetting agent (surfactant) will be used. Wetting agent is added to enhance the process of degreasing.

3.7 Exact quantity of chemicals is to be carried in dry form onto the drum level platform. The chemicals are to be dissolved in DM water externally in a container near the drum manhole in batches. The concentrated solutions so prepared are to be poured into the drum through the manhole. When the entire quantity of chemical has been so dissolved and poured into the drum, close the manhole. Raise the water level in the drum up to the light up level (2nd port in the gauge glass).

3.8 BOILER LIGHT UP

3.8.1 After ensuring the above, light up the unit and raise boiler pressure very slowly to closely monitor the thermal expansion of the pressure parts and no case pressure raising should not exceed cold start up pressure raising curve.

3.8.2 Ensure that the normal water level is maintained in the drum through out the boil out operation.

3.9 DURATION

Raise boiler pressure to 50% of working pressure (Drum) or 40kg/cm2 whichever is lower. Carry out the boil out operation by maintaining this pressure for a period of 12 hours. The pressure is to be maintained by controlling the fuel firing and modulation of the start up vent. During this process normal drum level to be ensured.

3.10 BLOWDOWN

On attaining approx, 5kg/cm2(g) drum pressure, quickly operate the intermittent blow down for 10 sec. Restore drum water level to N.W.L. Allow drum pressure to raise upto a value which is 50% of operating pressure or 40kg/cm2 (g) whichever is lower. Ensure that water level in the drum is replenished each time. Leave the CBD valve slightly open to prevent choking of sample line and sample cooler. Operate the IBD for 10 seconds once every hour.

With due care considering the firing conditions in side the combustor Each bottom header drains to be operated once in every hour for 30 sec one by one to remove the sediments from the bottom headers. It is advised to stop the firing or reducing the firing to very minimum to avoid any hot spots in the pressure parts which may done in consultation with the commissioning Engineer.

At the end of 12 hours of boil out operation, a sample of boiler water is tested for oil traces, to determine the end point of the process. Oil ppm should preferably be less than 5ppm.

If the oil levels are not coming down even after adequate draining, If required chemicals may be added to drum through HP dosing system.

After stopping the firing, operate all the bottom header drains for 30 – 45 sec to remove the sediments from the headers.

4.0 COMPLETION OF BOILOUT

4.1 Boiler water sample is analyzed for presence of oil. When analysis confirms that oil present in the sample, is within limits (=< 5 PPM) the boil out operations treated as complete.

Rinsing to be done to match the boiler pH very close to feed water pH.

For confirmation it is advised to collect 3 samples within 5 minutes of each other and check for consistency of results.

4.2 To neutralize the high pH drained water from blow down or from rinsing during blow out process, a neutralization pit to be installed and the boiler drain lines to be temporarily connected to that. To neutralize before draining into the trench, acid can be added and mixed by a stirrer or by air bubble.

5.0 POST BOIL OUT OPERATION

5.1 Box up the boiler and allow the unit to cool by natural cooling. When the drum pressure drops to 2 kg/cm2 open the drum air vent & start up vent.

5.2 When the drum pressure drops to atmospheric, drain the boiler by opening all valves on drain headers.

5.3 After draining the boiler, cut the inspection caps in all bottom headers. Inspect drum and bottom headers for any sediment and for cleaning and flushing.

In case of in bed evaporator coils both in bed coils bottom and top header end caps and inspection caps needs to be cut and inspected. It is to be ensured that all the drain holes in the baffle plates to be clean and free from any blockage / foreign materials like weld slag / welding consumables.

5.4 Open the steam and water drum manholes and remove the sediments (if any).

5.5 Back flushing of super heaters and Flushing of the drums down comer, supply pipes convection tubes thoroughly.

5.6 Re weld the end caps on headers as per the recommended procedures.

5.7 After welding radiography (if req.) Post weld heat treatment (if req.) hydro test of boiler to be completed to the maximum working pressure.

COMMISSIONING GENERAL GUIDELINES

COMMISSIONING GENERAL GUIDELINES

1.0 INTRODUCTION

This write up is based on my working experience in commissioning with a leading engineering consulting firm .  Commissioning  though the last activity but is  equally important  for  a new project. This is the last opportunity for the engineers to detect any left out problems  during the execution of the project, correct it, and put the plant into operation for its trouble free commercial operation. This is a team work requiring full co operation, better understanding  among Vendor (Supplier, Contractor ), Purchaser ( Owner ) and Consultant ( Engineer)  to make it easy and achieve best result.
2.0 COMMISSIONING
Commissioning is the process of taking Plant, equipment and systems from an agreed state of erection completion through the operation of checking, start up, tuning and testing to the state of commercial operation.
It is important to avoid the impression that ‘commissioning’ is simply “putting the Plant into operation”. Any installed Plant is purchased to a specification, so it should be tested over the full range of the specification. Testing methods, procedures and techniques applied should be conducted in accordance with standard practices and applicable codes and standards
Commercial Operation shall mean the completion of a definite period  full load run with all required tests fully completed. There must also be a joint agreement at Site that this state has been reached.
3.0. OBJECTIVES OF COMMISSIONING
Commissioning aims at achieving the following objectives:
3.1 Make the Plant available for commercial operation as soon as possible by preparation of the equipment and systems for reliable and trouble free operation. This may involve;
a) Inspection, pre-operational checks and preparation of the equipment for start up including specialized cleaning.
b) Trial run, initial operation, performance monitoring and proving validity of Plant operation instructions.
c) Problem analysis and solution identifying- establishing the reasons for any limitation of either performance or flexibility of operation.
3.2 Fulfilling statutory obligations and contractual requirements like demonstrating that the Plant is capable of safe and reliable operation and that it meets the design specifications and performance guarantees.
3.3 Compiling and documentation of equipment test and performance data for future reference and comparison using standard forms and procedures.

3.4 Training of Operation & Maintenance personnel.

4.0 BASIC STEPS IN COMMISSIONING
For the smooth commissioning of the Plant, all equipment and systems should be made ready at appropriate stages. Broadly, the activities comprising commissioning are carried out in the following steps/stages:
4.1 Planning and preparation
Planning for commissioning the Plant should start even during the early stages of contract award for the major equipment. Agreement should be reached on the procedures for the trial runs, start up, testing and on the activities like chemical cleaning, steam blowing and other commissioning activities. For effective mobilization of resources at Site and also for efficient monitoring a PERT chart or a bar chart for commissioning activities should be prepared.
4.2 Completion of Erection
This is normally considered an easily identifiable point and, when reached, implies that further activities can take place. However at Site it is not easily identified. Interpretation of “completion of erection” of even a simple item like pump/motor unit can vary considerably. Consider the following two situations:
a) Pump and Motor mechanically complete; electrical supply available from a temporary source; working fluid available through previously commissioned pipework; access poor, and
b) Pump and Motor erection mechanically complete; all labels fitted; the system is connected to permanent power supply with all protections tested; working fluid as in (a) and permanent access made ready.
It is probably fair to say that the Pump/Motor unit would operate equally well in both the situations, although with increased risk of trip and personal injury in case (a). The important point to note is that “completion of erection” must be clearly and unambiguously defined, the plant/equipment should be declared safe for operation according to the safety rules and must be cleared for commissioning by the Erection/Construction Department.

4.3 Pre-commissioning, Inspection Checks, establishing cleanliness
The first important commissioning activity at Site is Plant walk downs and the inspection and checking of equipment, before attempting to put them into service. This activity is meant to ensure erection completion, compliance of critical dimensions, tolerances, manual operation of equipment such as valves, dampers etc, to check physical free movement, operation of limit switches etc., removal of unwanted material and access facilities for maintenance and inspection. These checks should be specified in the associated commissioning check list documents. Various equipment pipework, pressure vessels etc. arriving at Site would require degreasing, application of protective coating, flushing of pipelines etc. These procedures must be clearly outlined and carried out.
4.4 Admission of working fluid
The term “fluid” here is used in a wide context. It can mean gas, steam, oil, water, air or electricity. This stage implies that the equipment has had all checks carried out to a state where it is considered safe to admit the working fluid.
It is important to consider the following points;
What is the source of working fluid and how is it controlled?
What are the implications of the working fluid if, a) everything is normal, and b) if circumstances are abnormal?
How much do we monitor the admission of the working fluid to detect abnormalities?
Time spent in considering the above is well spent because it can prevent major incidents on account of minor lapses.
4.5 Application of safety rules
All equipment must be covered by the existing safety rules before it is energized or the working fluid is admitted for the first time. The Constructors usually view the imposition of safety rules as a hindrance to their progress, but adherence to safety rules is very important and they should be strictly enforced.

4.6 Using the Plant’s Operation Personnel
The Plant’s Operation Personnel are used as much as possible during start up and commissioning, including the use of Plant Operators to energize permanent plant equipment. Subsequent to start up, testing and commissioning of the systems they will be turned over to the Plant’s O & M Personnel who will then be responsible for routine O & M. The Plant’s O&M Management is to be provided with a commissioning plan and schedule. Recognizing the importance of communication and interface with various Plant entities for the safe and efficient start up, Commissioning Engineers should notify the Control Room and the Plant’s Operating Personnel of ongoing commissioning activities on a regular basis.
4.7 Trial Run and Initial Operation
This activity normally takes place after the equipment has come under the safety rules and is witnessed by all interested parties.
It is important before this stage is reached to have agreed under what circumstances initial operation will take place. Compromises have to be reached on what is essential and what is desirable. It is therefore important to decide which items are essential and the Plant/equipment will not be run under any circumstances unless the requirements for these items are met. Often this tends to be a pressure area when Constructors can see that the Plant is almost ready to run and is only being held up for seemingly small items like say, alarms, indicators etc.
Wherever possible all rotating equipment must be individually trial run. Before the trial run, service facilities like, power, cooling water, lubricants etc., must be made available. Prior to trial run the drive unit (usually an electric motor) should be trial run in the uncoupled condition after carrying out the commissioning checks specified for that particular equipment. After successful completion of trial run of the drive, the equipment should be coupled and trial run for about eight (8) hours.
During the trial run the equipment should be carefully observed for any unusual noise, abnormal vibration or undue bearing temperature rise. Any defects should be immediately attended and trial run repeated till satisfactory results are obtained.
A record of trial run/initial operation including the vibration readings, bearing temperature rise, starting current, no load current, time for acceleration/deceleration, defects noticed, rectifications carried out etc., should be maintained for future reference.
4.8 System Checks and setting of parameters for operation regimes

When a system or sub-system has completed its initial operation, it then has to be checked for correct response to operational parameters, circumstances and that it follows the established operation regime (eg. protections, interlocks, permissives, auto start etc.) Sometimes it may be necessary to simulate inputs to test the response of the system. Frequently a system is part of much larger system, then as other parts of the overall system become available simulated checks are replaced by line checks. After these checks are carried out the system should be adjusted and set to operate as per the established regimes.

4.9 Performance Testing
The decision as to whether the Plant meets its major contractual and design criteria is taken on the results of Performance Tests on the major equipment and systems of the Plant. These are well defined in standard test codes and it is only necessary to agree to the logistics of carrying out such tests. It is important to carry out the tests strictly as per the agreed test codes to avoid any chances of a repeat test following any debate.

4.10 Training of Plant Operation & Maintenance Personnel
This is the last stage of the commissioning process. Since the Plant’s O & M Personnel are kept involved from the very beginning of commissioning activities it enables them to get familiar with the Plant and equipment specific operating procedures. The Commissioning Engineer at Site should suitably instruct the operating personnel on the operations involved in bringing new equipment to the full operation mode. Important operational safeguards and procedures should be highlighted and explained.

5.0 GENERAL COMMISSIONING GUIDELINES
a) All plant and equipment must be clearly identified with its agreed title/tag.
b) Lighting must be adequate to promote a safe working environment.
c) Safe access to and around the equipment being commissioned must be maintained at all times. Clearly identified escape routes should be provided.
d) Access to be restricted to personnel necessarily involved with commissioning. Temporary barriers may be required to inhibit access to unauthorized personnel.
e) Permanent fire protection equipment should be in service, augmented by additional staff and/or temporary fire extinguishers wherever necessary.
f) Plant being commissioned should be clearly marked with durable, easily noticed, self adhesive labels to warn personnel of equipment/systems which are about to start up and also of which section of the plant are subject to safety rules.

6.0 PLANT TURNOVER/TAKING OVER BY THE OWNER
After successful commissioning of Plant, equipment and systems and prior to turning the Plant over to the Owner, the Commissioning Engineer should participate in a walk down with the Owner of the Plant. Acknowledged deficient items will be corrected or added to the Project ‘punch list’ for completion after turnover to the Owner. Standard project turnover/taking over documentation and procedures should be used.