Refrigeration
Refrigeration piping of this specification sets out the standards of workmanship and materials for the supply and installation of pipes and fittings for the Air Cooled Condensing System.
Piping Materials and Insulation
Refrigerant pipework of up to and including 2 in” bore pipes shall be of copper to BS 659. Condensate drain pipes shall be of uPVC material.
The factory assembly plant shall be insulated as recommended by the manufacturer and applied at the manufacturer's factory during or after assembly. The whole of the cold refrigerant pipelines installed at site including gas suction line, all fittings, solenoid valves, strainers, flanges, etc shall be insulated with minimum 1½" thick armaflex insulation or approved equivalent and vapour sealed with aluminium foil and painted with the appropriate and approved emulsion in two coats.
Condensate drain pipes shall be insulated with 1" thick armaflex insulation or equivalent material to approval.
Copper Pipe Jointings
All joints in copper tubing up to and including 1½" diameter shall be made with approved capillary fittings or may be brazed. All joints in copper tubing 2" dia
meter and above shall be made with flanged connections or may be brazed.
All brazed joints shall be silver soldered using a hard solder, containing not less than 15% silver. No acid-based flux or fluid shall be permitted under any circumstances.
The joints shall be thoroughly cleaned and washed to remove all traces of flux after the joints have been soldered.
All welding joints shall be done by approved competent welders.
Where connections are made to valves and equipment, flanged joints shall be used. All flanges shall be bronze flanges to B.S. 10 Table E or F as necessary.
Copper Pipe Fittings
Fittings in all cases shall be suitable for their application.
Fittings up to and including 1½" dia meter shall be of the capillary or compression type and fittings of size 2 ins diameter and above shall be of the flanged type.
In all piping, bends shall have a radius not less than five times the diameter. If this radius cannot be obtained, alternative bends of approved type shall be type shall be used.
All tees in the pipework shall be completely brazed. Oversize holes, filled in with brazing after the joint has been made will not be permitted.
Reductions in diameter for through-flow pipes shall be made by means of reducing sockets. Eccentric reducing sockets shall be used on horizontal pipes only.
Pipe Supports
All piping shall be so installed and supported that it will permit free contraction expansion without damage to the joints, hangers and any other work or effect damage to itself. Chain, wire or other makeshift devices will not be permitted.
Minimum pipe support spacing shall not be less than 8 feet.
Additional supports shall be provided at all concentrated loads (large valves etc) or where changes in the direction of piping system occurs between hangers and any other work or effect damage to itself. Chain, wire or other makeshift devices will not be permitted.
All fixing of pipe hangers or brackets to the building structure shall be by means of approved nylon or metal expansion plugs.
Expansion Joints and Anchors
Wherever possible, changes in direction of pipes to accommodation expansion and contraction due to temperature changes of the pipe and its contents, shall be taken advantage of.
All pipes shall be anchored as required to control the movement & of pipes due to thermal changes Anchor shall also be fitted at the lower end of the vertical & pipes. The anchors shall hold the pipe securely in a fixed position to resist the attempted movement due to expansion and the self weight of the pipe and its contents.
Refrigerant Piping Sizing
The Sub-Contractor shall along with the tender/quotation submit details of Refrigerant pipe sizing showing pressure loss etc. Failure to submit this information may result in disqualification of the tender.