- SCOPE
- REFERENCE
- RESOURCEs
- EXECUTION PROCEDURE
- SAFETY ASPECT
1.0 SCOPE:
This document covers the requirements and procedures for installation of HVAC system at the PROJECT (EPC-12). And to ensure that the work is performed in accordance with the Project Specifications and IFC drawings.
2.0 REFERENCES:
HVAC Heating, Ventilation and Air Conditioning
ASHRAE American Society of Heating and Refrigeration Association of Engineers
NFPA National Fire Protection Association
SMACNA Sheet Metal Air Conditioning National Association
UMC Uniform Mechanical Code
ANSI American National Standards Institute
AMCA Air Movement & Control Association International
ASTM American Society for Testing & Materials
ASME American Society of Mechanical Engineers
AABC Associated Air Balance Council
SATIP Saudi Aramco Typical Inspection Plan
SAMSS Saudi Aramco Materials System Specification
SAES-S-060
3.0 RESOURCES
Tools Required
• Lifting Equipment
• Hand Tools
• Generator
Materials
• Galvanized Zinc. coating Iron Sheets
• Duct Sealant
• Angles and supports
• Scaffolding
• Hardware
• Insulation Materials
• Aluminum Cladding
• Accessories as per approved IFC drawings.
Manpower
• Site Engineers
• QC inspector
• Safety Officer
• Supervisors
• Technicians
• Labor
4. EXECUTION PROCEDURE:
4.1 REFRIGERANT PIPE INSTALLATION:
Take extreme care to keep refrigerant tubing/piping clean and dry prior to installation. The Following procedures should be followed:
1) Use only refrigeration grade copper tubing CU-B280 properly sealed against contamination. Copper tubing often contains wax and other trouble-some contaminants. Ensure that this is checked.
2) Refrigerant piping on split system should be designed and installed in accordance with approved IFC drawing.
3) The horizontal sections of the suction line should always slope towards the condensing unit. There should be 1/2 inch drop for each 10 feet of line, which is sufficient to return oil.
4) Suitable P-type oil traps should be located at the base of each suction riser.
5) The oil trap can be constructed with three elbows and is installed at the base of suction risers which carry gas on upward flow.
6) No trap should be placed directly ahead of the compressor. This is to prevent slugging of the compressor with oil or liquid refrigerant trapped there.
7) Sealed type liquid line filter driers are recommended in smaller capacity units and replaceable core type driers are recommended on higher capacity units. In both cases, do not leave the filter drier open to the atmosphere any longer than absolutely necessary.
8) Suction lines must be insulated with thermal insulation to prevent condensation. Liquid lines require no insulation unless they run through high temperature areas.
9) Always consult with the concerned engineer for more detailed piping method according to site applications.
10) All piping should be kept short and with as few fittings as possible. This is to prevent excessive pressure drop in the lines. Do not clamp the lines together without insulation, unless it is necessary to use them to provide a heat exchanger.
11) Lines should never be left loose or unsupported. Isolation or vibration-free hangers are to be used. Do not attach lines directly to a building to eliminate vibration and noise.
12) All Refrigerant line shall be purged with 7 KPa gauge (1.0 psig) dry nitrogen while soldering, brazing or welding connections.
13) Refrigerant piping placed underground shall be protected against corrosion.
14) Supports for refrigeration piping shall be noncombustible.
15) Refrigerant piping and tubing shall be securely fastened to a permanent support within 6 feet (1.8m) following the first bend in such tubing from the compressor and within 2 feet (610mm) of each subsequent bend or angle.
16) Refrigerant piping and tubing shall be supported at points not more than 15 feet (4570 mm) apart.
17) Refrigerant piping shall not be located within a required exit.
18) The direction of flow and Type of line shall be indicated on refrigerant piping.
19) Color code for both the lines liquid and gas lines as per the ARAMCO standard will be provided
4.2 PIPE INSULATION AND CLADDING:
- Refrigerant suction lines shall be insulated from the evaporator to the compressor.
- Pipe work insulation shall have a flame spread/smoke developed rating not in accordance with project specification of factory pre molded fiber glass noncombustible to ASTM C 518 with a thermal transmittance not greater than 0.032 WIm2K at 24C.
- Piping insulation shall be applied only where the Pressure test and other inspections required are completed.
- Before insulation, all surfaces shall be thoroughly cleaned to remove slag, rust, grease, etc. Insulation shall be applied only on dry surface.
- Insulation installed outdoors shall be protected from moisture and sunlight degradation by 0.5mm (26 gauge) aluminum jacket or an approved and acceptable method.
- Outdoor insulated piping shall be finished with aluminum sheet 0.5 mm (26 gauge) thicknesses, and all seams and joints shall be caulked.
5.0 SAFETY
5.1 GUIDELINES: Person working with ducting work shall wear the personal protective equipment’s at all times on the job site. Warning sign boards and light shall also be provided where necessary.
5.2 RESPONSIBILITIES: Safety Inspector/Officer in conjunction with the site supervisor or foreman shall physically check and conform that all safety requirements had been provided and implemented.
JOB HAZARD ANALYSIS FOR REFRIGERANT PIPING WORKS AND INSULATION