GUIDE SPECIFICATION SECTION232313-1
Revised 16 February 2016Refrigerant Piping
SECTION 232313 - REFRIGERANT PIPING
PART 1 GENERAL
RELATED DOCUMENTS
Drawings and general provisions of Contract, including General and Supplementary Conditions and Division1 Specification sections, apply to work of this section.
QUALITY ASSURANCE
ANSI/ASME Compliance: Fabricate and install refrigerant piping in accordance with ANSI B31.5 Refrigeration Piping and Heat Transfer Components.
ASHRAE Compliance: Fabricate and install refrigerant piping in accordance with ASHRAE 15 Safety Code for Refrigeration Systems.
SUBMITTALS
General: Submittals shall demonstrate compliance with technical requirements by reference to each subsection of this specification. Where a submitted item does not comply fully with each and every requirement of the Specifications, the submittal shall clearly indicate such deviations. Identification requirements for non-complying features of items are very specific. See Section 230210 for exact requirements.
Manufacturer's Data: Submit manufacturer's technical product data and installation instructions for refrigerant piping materials and products.
PART 2 PRODUCTS
COPPER PIPING
Piping Materials: Provide pipe and tube of type, joint type, grade, size and weight (wall thickness or Class) indicated for each service. Where type, grade or class is not indicated, provide proper selection as determined by Installer for installation requirements, and comply with governing regulations and industry standards.
Size 1" and Larger: Utilize copper tube in compliance with ASTM B88, Type K, harddrawn temper, wroughtcopper, brazedjoint fittings, brazed joints.
Size 3/4" and Smaller: Utilize copper tube in compliance with ASTM B 280, Type ACR, soft annealed temper fittings, cast copperalloy fittings for flared copper tubes; flared joints.
Brazed Joints: Brazed joints using brazing alloy in compliance with ASTM B32. Use silver brazing alloy.
COPPER FITTINGS
Pipe/Tube Fittings: Provide factoryfabricated fittings of type, materials, grade, class and pressure rating indicated for each service and pipe size. Provide sizes and types matching pipe, tube, valve or equipment connection in each case. Where not otherwise indicated, comply with governing regulations and industry standards for selections, and with pipe manufacturer's recommendations where applicable.
Copper BrazedJoint Fittings: Cast copper per ANSI B16.18 or wrought copper per ANSI B16.22, with “type” to match adjacent piping.
Brass Pipe Flanges: ANSI B16.1, cast brass, with heavy head machine bolts or cap screws, ASTM A193-B7 steel alloy, with hex full nuts, Type 304 stainless steel per ASTM A194-Gr. 2H. Gasket shall be 1/8” natural rubber, 35-45 Durometer hardness.
CopperTube Unions: Provide standard products recommended by manufacturer for use in service indicated.
Piping Connectors for Dissimilar NonPressure Pipe: Elastomeric annular ring insert, or elastomeric flexible coupling secured at each end with stainless steel clamps, sized for exact fit to pipe ends and subject to approval by plumbing code.
REFRIGERANT VALVES
Service and Check Valves:
Service Shutoff Valves: Forged brass, packed, back seating, winged seal cap, 300 deg. F temperature rating, 500 psi working pressure.
Check Valves: Forged brass, accessible internal parts, soft synthetic seat, fully guided brass piston and stainless steel spring, 250 deg. F temperature rating, 500 psi working pressure.
Solenoid Valves:
2Way Solenoid Valves: Forged brass, designed to conform to ARI 760 and UL 429, normally closed, teflon valve seat, NEMA 1 solenoid enclosure, 24 volt, 60 Hz., Listed, 1/2" conduit adapter, 250 deg. F temperature rating, 400 psi working pressure. Provide manual operator to open valve.
Safety Relief Valves: Comply with ASME Boiler and Pressure Vessel Code, Listed and Labeled. Valve construction and ratings shall be as follows:
Body and Bonnet: Ductile iron and steel, with neoprene O-ring seal.
Piston, Closing Spring, and Seat Insert: Stainless steel.
Seat Disc: Polytetrafluoroethylene.
End Connections: Threaded.
Working Pressure Rating: 400 psig.
Maximum Operating Temperature: 240 degF.
Thermostatic Expansion Valves: Comply with ARI750. Incorporate reverse-flow option for heat-pump applications. Valve construction and ratings shall be as follows:
Body, Bonnet, and Seal Cap: Forged brass or steel.
Diaphragm, Piston, Closing Spring, and Seat Insert: Stainless steel.
Packing and Gaskets: Non-asbestos.
Capillary and Bulb: Copper tubing filled with refrigerant charge.
Suction Temperature: 40 degF.
Superheat: Adjustable.
Working Pressure Rating: 450 psig.
Hot-Gas Bypass Valves: Comply with UL429. Valve construction and ratings shall be as follows:
Body, Bonnet, and Seal Cap: Ductile iron or steel.
Diaphragm, Piston, Closing Spring, and Seat Insert: Stainless steel.
Packing and Gaskets: Non-asbestos.
Solenoid Tube, Plunger, Closing Spring, and Seat Orifice: Stainless steel.
Seat: Polytetrafluoroethylene.
Equalizer: Internal.
Electrical: Molded, watertight coil in NEMA250 enclosure of type required by location with 1/2-inch (16-GRC) conduit adapter.
Throttling Range: Maximum 5 psig.
Working Pressure Rating: 500 psig.
Maximum Operating Temperature: 240 degF.
REFRIGERANT SPECIALTIES
Refrigerant Strainers: Brass shell and end connections, brazed joints, monel screen, 100 mesh, Listed, 500 psig working pressure.
MoistureLiquid Indicators: Forged brass, single port, removable cap, fused glass, 240 deg. F temperature rating, 500 psi working pressure.
Evaporator Pressure Regulators: Provide corrosionresistant, spring loaded, stainless steel springs, pressure operated, evaporator pressure regulator, in size and working pressure indicated, with copper connections.
Refrigerant Discharge Line Mufflers: Provide discharge line mufflers as recommended by equipment manufacturer for use in service indicated.
Refrigerant Discharge Line Oil Separator: Separator shall be high efficiency centrifugal type designed for use with the type of refrigerant in the system, rated for at least 450 psig working pressure.
Replaceable-Core Filter Dryers: Provide filter dryers in compliance with ARI730. Body and cover shall be painted-steel shell with ductile-iron cover, stainless-steel screws, and neoprene gaskets. Filter media shall be 10 micron, pleated with integral end rings; stainless-steel support. Working pressure rating of 500 psig and maximum operating temperature of 240 degF.
Flexible Connectors: Connectors shall have stainless-steel bellows with woven, flexible, stainless-steel-wire-reinforced protective jacket. Connector shall be capable of minimum 3/4-inchmisalignment in minimum 7-inch-long assembly. Factory test at minimum of 500 psig and maximum operating temperature of 250 degF.
PART 3 EXECUTION
PIPING INSTALLATION
Regardless of refrigerant piping configuration, routing, and sizes indicated on the Drawings, Contractor shall verify pipe sizing to complement length and elevation of pipingas installed. As necessary include all piping accessories necessary to complement length and elevation of piping.
Select system components with pressure rating equal to or greater than system operating pressure.
Install refrigerant piping according to ASHRAE15, as follows:
Install piping in concealed locations unless otherwise indicated and except in equipment rooms and service areas.
Install piping indicated to be exposed and piping in equipment rooms and service areas at right angles or parallel to building walls. Diagonal runs are prohibited unless specifically indicated otherwise.
Install piping above accessible ceilings to allow sufficient space for ceiling panel removal.
Install piping adjacent to machines to allow service and maintenance.
Install piping free of sags and bends.
Install fittings for changes in direction and branch connections.
Install piping as short and direct as possible, with a minimum number of joints, elbows, and fittings.
Arrange piping to allow inspection and service of refrigeration equipment. Install valves and specialties in accessible locations to allow for service and inspection.
Install piping with adequate clearance between pipe and adjacent walls and hangers or between pipes for insulation installation.
Slope refrigerant piping as follows:
Install horizontal hot-gas discharge piping with a uniform slope downward away from compressor.
Install horizontal suction lines with a uniform slope downward to compressor.
Use double-suction riser for maximum compressor efficiencies if load variation is expected.
Install traps and double risers to entrain oil in vertical runs.
Liquid lines may be installed level.
When brazing or soldering, remove solenoid-valve coils and sight glasses; also remove valve stems, seats, and packing, and accessible internal parts of refrigerant specialties. Do not apply heat near expansion-valve bulb.
Protect refrigerant piping as follows:
Install underground refrigerant piping in protective PVC piping or conduit.
Install refrigerant piping in rigid or flexible conduit in locations where exposed to mechanical injury.
PIPE JOINT CONSTRUCTION
Remove scale, slag, dirt, and debris from inside and outside of pipe and fittings before assembly.
Construct solder joints according to ASTMB828 or CDA's Copper Tube Handbook.
Construct brazed joints according to AWS's Brazing Handbook, Chapter "Pipe and Tube."
Use Type BcuP, copper-phosphorus alloy for joining copper socket fittings with copper pipe.
Use Type BAg, cadmium-free silver alloy for joining copper with bronze or steel.
For flanged joints, select appropriate gasket material, size, type, and thickness for service application. Install gasket concentrically positioned. Use suitable lubricants on bolt threads.
VALVE AND SPECIALTY APPLICATIONS
Refrigerant valves and specialties shall be installed for each refrigerant system either as an original equipment manufacturer (OEM) installation or field-installed, as follows:
Install line-sized shutoff valves and flexible connectors in suction and discharge lines of each compressor.
Install line-sized shutoff valves on each side of other refrigeration equipment, including condensers, evaporators, receivers, etc. in multiple unit installations.
Install service valves for gage taps at strainers if they are not an integral part of strainers.
Install a check valve at the compressor discharge and a liquid accumulator at the compressor suction connection.
Install filter dryers in liquid line between compressor and thermostatic expansion valveand in the suction line at each compressor, complete with full-sized three-valve bypass around filter dryers utilizing line-sized shutoff valves, so that filter dryer may be replaced while system remains in operation. Filter dryers shall be installed in the horizontal position, except that replaceable core filter dryers may be installed in the vertical position with the access flange on the bottom.
Install solenoid valves upstream from each expansion valve. Install solenoid valves in horizontal lines with operator at top.
Install thermostatic expansion valves as close as possible to distributors on evaporators. Install valve so diaphragm case is warmer than bulb. Secure bulb to clean, straight, horizontal section of suction line using two bulb straps. Locate bulb on top of the suction line smaller than 2-1/8" OD and at the 4 o'clock or 8 o'clock position on larger lines. If external equalizer lines are required, make connection where it will reflect suction-line pressure at bulb location.
Where required by the compressor manufacturer, install discharge line oil separator on the discharge of each compressor, downstream of the flexible connector and/or discharge muffler, securely anchored to the unit. Oil return shall be connected to the compressor in accordance with manufacturer recommendations.
Install safety relief valves where required by ASME Boiler and Pressure Vessel Code. Pipe safety relief valve discharge line to outside according to ASHRAE Standard 15.
Install moisture/liquid indicators in liquid line at the inlet of the thermostatic expansion valve or at the inlet of the evaporator coil capillary tube.
Install strainers upstream from and adjacent to the following unless they are furnished as an integral OEM assembly for device being protected:
Solenoid valves
Expansion devices
Compressors
FIELD QUALITY CONTROL
Clean and test refrigerant piping in accordance with ANSI B31.5, Chapter VI. Perform initial test with dry nitrogen, using soap solution to test all joints. Perform final test with 27" vacuum, and then 200 psi using electronic leak detector. System must be entirely leakfree. Submit leak test reports to A-E for review.
Repair or replace refrigerant piping as required to eliminate leaks, and retest as specified to demonstrate compliance.
DEHYDRATION AND CHARGING SYSTEM
Install core in filter dryer after leak test but before evacuation.
Evacuate refrigerant system with vacuum pump to 500 micrometers. If vacuum holds for 12 hours, system is ready for charging.
Break vacuum with refrigerant gas, allow pressure to build up to 2 psig.
Complete charging of system, using new filter dryer core in charging line. Provide full operating charge.
OWNER INSTRUCTION AND TRAINING
Provide Owner instruction and training in accordance with Section 230240.