This method statement covers all processes related to Testing & Commissioning of Laboratory Gas System, procedure is to be read in conjunction with the relevant ITP, outlining the responsibility and the quality verification to be performed by various parties.
Project manager is overall responsible to make sure that all installations and testing activities are done as per approved shop drawings and specifications for the required and applicable areas for gas piping system.
Project team will ensure that all works are carried out as per requirements of project quality and HSE plan.
All Quality Assurance and Quality Control activities shall be in line with the Sub Contractor’s Quality Management System and as required by the Project Specification, approved Inspection and Test Plans, etc.
Necessary Tools and Equipment
- Tool box
- Hand Tools
- Steel cutting Chop-saw
- Measuring tape
- Marker
- Pressure testing gauges
- Wire brush
- Drill machine
- Grinding Disc
- Screw driver (flat & set)
- Fix spanner (4mm to 32 mm)
- Adjustable spanner
- Safety requirements tools such as safety shoes, safety helmet, safety glasses, fluorescent vest, and safety gloves to ensure maximum ability of safe work and dust mask when required.
- Gas Cylinder
- Access Ladder
- Orbit Welding machine and accessories
- Cutting & Bending machine
- Instrumentation tool
Material Handling and Storage
Materials such as fittings, clamps, screws, anchors as well as small valves, gauges, support etc. stored inside boxes can be unloaded manually from the pick-up truck to the site store.
Tube, Pipes, manifold, shall be unloaded from the pick-up manually in single bundles, otherwise if forklift is available, it shall be used to minimize manual handling.
Manual handling shall be carried out in accordance with suitable safety procedures.
Material such as pipe fittings, clamps, screws and anchors as well as small valves, gauges, fittings, support etc. shall be kept in a suitable place inside the work site /site store accessible for easy storage and collection.
SS Tube & Pipe shall be kept in a rack or stacked up in an area where falling, slipping, and rolling or any uncontrolled motion is negligible
Tools shall be kept in their respective tool boxes and stored in the site store.
Material Shifting to work area
Materials such as pipe fittings, clamps, screws, small valve, gauge, regulator etc. packed inside the boxes can be carried by hand and transferred to the working site area
Tube, Pipe and heavy materials from main store to different area levels will be transferred through hoist.
Material transfer shall be under the project logistic procedures.
Health and Safety Requirements
Ensure only trained persons shall operate the power tools & other related instruments such as multimeter, ammeter etc.
All personnel shall use PPE (Personal Protective Equipment) and all other items as required.
Ensure adequate lighting is provided in the working area at night time.
Make sure service area/work area openings are provided with barricade, tape, and safety nets.
Ensure that all people engaged in the Testing & Commissioning of Laboratory Gas System experienced & have received proper & adequate training related to procedures & test equipment utilized for the particular activity.
Test instruments and test leads should be maintained in a safe condition and test methods enable not to create danger on either the operator or other personnel.
Where tests are required to circuits which are live for Amp. readings, the tightness of the cable terminations shall be checked without power prior to readings.
Ensure that the area around the pipe welding is cordoned or barricaded & with temporary scaffold if necessary.
Ensure that warning labels are available on the GLD panels.
Testing & Commissioning Procedure
After the satisfactory installation checks on the installation of Laboratory Gas System; Commissioning will commence.
The results shall be recorded on the commissioning test report and the commissioning test sheet.
Subject to the formal acceptance of the consultant, the gas installations may be progressed in sections with respect to testing.
Any balance works will be completed or rectified as applicable and re-tested before continuing to the next stage of testing.
Nitrogen shall be used for the purpose of testing & purging and the like, at no circumstances, industrial air shall be accepted for the purpose of testing or purging.
Open all the valves in between the piping section, where the test has to be carried out and connect this section to the Nitrogen cylinder.
The system(s) will be fully charged with Nitrogen and the cylinder valve closed and the cylinder disconnected.
The test pressure 1.5 times of the design pressure shall be held for a minimum of 24 hours, or as directed by the consultant.
Leakage can be identified by means of soap solution applied to weld joints, valves, connections etc.
All leaks will be rectified and test repeated until the pressure can be held for 24 hours.
Once the pressure is found holding for the set period, the system is ready to be connected to the equipment’s.
The gas manifolds are to be connected to the pipe system and the leak checks for the connected joints to be carried out at operating pressures.
After commissioning has done, results will be recorded on the Check list with acceptance & approval signature by the consultant/client.
Gas Manifold Automatic Changeover
Be sure that both ends of all hoses or pigtails are secured before pressurizing.
Turn the line regulator knob anti-clockwise until the knob stops turning.
When first pressurizing, do not stand in front of or contact the switchover system.
Slowly open the cylinder valve.
Observe the high pressure gauge for a rise in pressure up to full cylinder pressure.
Warning – if this system is equipped without the line regulator, the outlet will pressurize when the cylinder valve is opened.
Keep the hand wheel or wrench on the open cylinder valve at all times, to allow prompt emergency shut-off.
Inspect all connections for leaks and fix any leaks.
A leak detection solution may be applied to the connections (if compatible with the application), which indicates leaks by bubbling.
To further check for leaks, or if the leak detection solution cannot be used, close the cylinder valve for a period of time (recommended 24 hours), and observe the high pressure gauge for a drop in pressure. If so indicated, recheck the connection and all other high-pressure port connections.
Never attempt to fix a leak under pressure.
If leaks are detected, depressurize the system and retighten the connection.
Begin again the gas pipe pressure testing as per the above steps.
Slowly turn the line regulator knob clockwise.
This will increase the pressure of the line.
Adjust to the desired working pressure and again check for leaks using the methods described above.
Also follow all the manufacturer instructions for manifold operation.
Pressure control regulator will be provided before the fume hood outlet with service valve, Fine Control Needle Valve.
Gas Control Panel Testing
Switch ON the power to the Main Gas Control Panel of each zone panel and check the following functions:
Normal Operation of the Gas Control Panel
During normal operation, the LED for POWER on the luminous band and GAS VALVE ON indicates on the Indicator panel (HMI panel) and the gas solenoid valves will be energized.
Operation of the FAULT Indications
Disconnect the main power supply (240V AC) & confirm that the AC-FAIL indicates on the HMI panel and now the gas panel will work on backup battery (Approx. for 2 hrs.).
Connect back the main power supply (240VAC) and confirm indication is normal on HMI panel.
Disconnect the battery backup (24V DC) & confirm the DC-FAIL indicates on the HMI panel and gas panel will work on the main power.
Create an open circuit in any of the detector cabling and confirm the operation of FAULT LED on the indication cards, to verify the monitoring of the feed lines and power to the gas detector.
Operation of the Gas System Shut Down
- Push the EMERGENCY STOP key switch on the front of the panel door and confirm that the sounder strobe operates, the GAS VALVE OFF indicates on HMI panel and the gas solenoid valve will get de-energized.
- Press RESET button on the front panel door to acknowledge the above alarm and mute the sounder strobe.
- Release the EMERGENCY KEY SWITCH and confirm the GAS VALVE ON indicates on the HMI panel and the gas solenoid valve will get energized.
Operational Test of the F.A.P. Interlink / Interface
Check all cables and wiring connection from Gas Control Panel to the zone fire alarm control panel is done.
Simulate any fire alarm detector of the zone; a fire signal through normally open contact of the fire panel is send to gas panel.
Confirm that the gas solenoid valve is de-energized, GAS VALVE OFF and FIRE indicates on the Gas Control Panel (HMI panel).
Restore the Gas Control Panel by restoring the FAP to normal.
Gas Leak Detection System Testing
Perform operational Test of the Gas Detection System as below:
Activate any of the gas detectors inside the laboratory/corridor by giving gas and confirm that the luminous band on the corresponding indication card of the Gas Panel displays the prevailing gas concentration of each individual zone.
Once the measured gas concentration exceeds preset point of Alarm-1 (15% E.L.) indicated in the gas panel, confirm that the sounder strobe operates and Alarm-1 LED on the indication card glows.
As soon as the measured value exceeds preset point of Alarm-2 (30% E.L.), confirm that the sounder strobe operates, Alarm-2 LED on the indication card of the gas panel glows, gas solenoid valve gets de-energized, indication for GAS VALVE OFF glows.
Press RESET button in the panel door to acknowledge the above alarms and to mute the sounder strobe.
The system can be restored to Normal Operation by pressing the RESET button once again as soon as the gas concentration falls below Alarm-2 set limit (30% E.L.)
Prior to confirming the completion of the commissioning of the Gas Leak Detection System, set the Gas Control Panel in normal condition.
Check all the sensors of the system as per the above procedure and complete the testing and commissioning sheet.
Ensure that the detector has been connected to the mains.
Spray test gas into the vents on the front panel of the detector until the RED LED switches ON and the buzzer sounds intermittently.
Continue to spray the test gas, after around 15 seconds the relay is activated and closes the solenoid valve.
Stop spraying the test gas into the detector vents and wait for a few seconds, the detector returns to normal operation and all alarm signals will be reset. The relay is deactivated.
Solenoid Valve Testing
The solenoid valves in the ZV’s are tested in combination with the Building ZAP Panel.
Charge the N2 gas from the manifold by energizing the solenoid valve to the associated piping.
The valves will be in the open position and will be passing the N2 gas through it until the pressure in the system is achieved.
Activate the gas detector by spraying gas and confirm that the luminous band on the corresponding indication card of the Gas Panel for the building displays the prevailing gas concentration of the zone.
When the leak is sensed by the gas detector, the Gas Panel calls for a “System Emergency Shut Down”, the solenoid valve will be de- energized and it will be shut down.
The system can be restored to Normal Operation by pressing the RESET button in the Gas Control Panel of the building.
Line filter for the valve to be close, while purging with other gases in zone valve, use with the same gases, for the final commissioning of filter.
Gas Alarm Panel (Cylinder Alarm Panel) Testing Method
Check all cables and wiring connection from Gas alarm Panel to the fire alarm control panel F.A.P is done.
Switch on the Gas Alarm panel.
Gas cylinder is low i.e.: on reserve or low pressure, indicator will remain lit.
To prove system on normal pressure cylinder, turn off cylinder and allow pressure to fall.
The alarm should sound and the Reserve lamp will light followed by the Low pressure lamp.
Mute the alarm with the mute button, this stops the alarm, but the light will remain on until cylinder is turned back on. c
Test all channels as above.
Contact gauge on the Right-Left side of the manifold is used in conjunction with Gas Alarm panel.
Providing the alarm for both banks are about to be depleted.
The contact alarm gauges have a normally open switch.
When the indicated pressure is above the gauge set point, the switch is closed and will allow current flow in the circuit.
Pressure Switch Testing
Pressure switch installed in the downstream of the Zone Valve /manifold regulator will sense the outlet pressure flowing to the system.
In case of any failure/Malfunction of upstream regulator, Line pressure increase below the preset conditions will activate the “System Emergency Shut Down”.
The Pressure switch in the ZV’s are tested in combination with the Building ZAP Panel.
Line Regulator:
Gradually open the inlet isolation valve to the regulator(s).
The regulator(s) are adjustable to deliver an outlet pressure of 0-10 bar as per the downstream system requirement.
Pressure Gauge /Pressure Rating
Pressure rating will be monitored by the pressure gauges, for each pressure reducing station (Provided 1st.& 2nd. Stages)
Training of Personnel
After acceptance of the Testing & Commissioning of Laboratory Gas Equipment, contractor shall inform the preferred schedule to the consultant for conducting a Training of personnel for the Operation & Maintenance of the gas system.
All attendees shall be trained for the proper operation of the system and functions of all safety devices & controls.
The training shall be conducted by a qualified & well experienced staff of the contractor or manufacturer representative.
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