Method statement template is a document which anybody can use for creating the method statement from scratch. A good method statement template may elaborate some examples in order to easily understand the intention of the sections of the document. I am giving here a complete a thoroughly reviewed method statement template which talks about the minimum contents of a method of statement. Where necessary I have given pictures/images/sketches etc to explain the work flow.
Below is a complete method statement template in which I have given some guide lines and actual text which you will need to change as per the required method statement is in italic font.
In this section you can briefly mention the purpose of the method statement which normally just tells that which activity you are going to cover and why it is required.
To establish a standard maintenance procedure during compressor replacement on Air-conditioning units and refrigeration system. This will also serve as a guideline for newly hired employee which will be dealing with Air conditioning unit Maintenance activity.
2. Scope Of Work
This section tells about the scope of work i.e. in which area, building, block or equipment the method will be applied, also including the duration is recommended for validity of a method of statement.
The scope of this standard method statement covers all equipment at the project which uses refrigerant compressor that may include Chiller Units, Package Units, Split A/C Units, Cold Store Units, Window Type A/C’s, etc. The method statement is applicable for a period of one year as per contract.
Include brief responsibilities of all personnel who will be involved for execution of the work for which you are going to write a method statement.
It is the responsibility of the A/C Technician to replace the damage compressor either with a new one or a used unit. The Supervisor and the Site Engineer should make sure that this maintenance procedure will be followed during the maintenance activities.
Include the abbreviations and terms which you will use in method statement.
- MST: Method Statement
- AM: Area Manager
- PM: Project Manager
5. Installation Procedure / Method Statement
This is the main area where the focus should be more while writing a method statement. You can split this section in two part i.e. pre-requirements and then actual procedure.
Try to write in short sentences the natural flow of work, where required include figures and images mentioned in the project specifications or related standards. Try to give references to other procedure or standards where required.
For your understanding below is a complete procedure.
- Prior to the work, wear safety shoes, goggles and gloves. It is also advice to place a Fire Extinguisher near the site during brazing.
- Prepare all tools and equipment to be used in replacing the refrigerant compressor like gas cylinder, gauge manifold, brazing set, brazing rod, flaring tool, spanner, adjustable wrench, vacuum pump, clamp ammeter, screw driver, etc.
- Remove the refrigerant from the system.
- Dismantle the old compressor unit either by cutting the suction and discharge pipe or removing the flare connection.
- Use dry nitrogen to push some of the contaminants out of the system by simply attaching the nitrogen regulator to one of the lines and allowing it to blow out the other. Do not exceed the system working pressure with nitrogen. Without compressor in the system, you can safely use 250 psig for high pressure refrigerant systems.
- Disconnect the pipeline before the expansion valve device where a liquid line filter can be installed later.
- Purge the Nitrogen through the liquid line toward the compressor.
- Disconnect the nitrogen after pushing off all contaminants on this point.
- Connect the nitrogen to the expansion device side of the liquid line. This line may be purged toward the compressor suction line.
- Install the liquid line filter just before the metering device (expansion valve) to prevent contamination from restricting the refrigerant flow.
- Install the new refrigerant compressor by either brazing the suction and discharge line to their corresponding connections or by using flare connection (See Brazing Procedure and Making Flare Connection Procedure). If used compressor is to be installed, change the oil first by specified grade (either 3GS or 4GS).
- Conduct leak testing using standing pressure test.
- Isolate the compressor by front seating the suction and discharge valve of the compressor.
- Charge the system with dry nitrogen until pressure reaches 150 psig. Do not pressurize any system above its working pressure as written on the label of the equipment.
- Let the system stand for a while and check the pressure gauge, if the reading falls, there is al leak
- Conduct system evacuation using a vacuum pump (See Evacuation Procedure).
- Charge the system with refrigerant (please refer to refrigerant charging procedure). Make sure that suction and discharge pressure will be 60 to 69 psig and 250 to 275 psig respectively.
- Start the system and keep it running as long as practical to circulate the refrigerant through the filter drier.
- Conduct current reading on the compressor and on the fan motor.
- Check the discharge air temperature of the evaporator if cooling is evident.
- Prepare report and list all details and equipment parameters after work done.
Give in bullets the forms and documents related to the method statement template.
- Inspection Checklist
- Applicable Standards
- Referenced procedure no 1