23 23 00 REFRIGERANT PIPING

.01 Refrigeration (General)

1. Where water cooled condensing units are specified, cooling towers or evaporative condensers shall be utilized.  Cooling water to waste systems are not permitted. 
2. Where defrost units are required, they shall be electrically operated with adequate space provided to replace defrost elements.  Defrost should not be limited to electrical units.  In larger installations hot gas defrost is preferred.
3. Installations shall be provided with necessary protective devices including, but not limited to electric overload devices, low suction pressure cutouts (manual reset), high head pressure cutouts (manual reset), low lube oil pressure cutouts (manual reset), oil traps, crankcase heaters, and anti-recycling.
4. Systems shall be designed for 95°F outdoor ambient summer conditions and where winter operation is desired, 0°F conditions.
5. All installations shall be performed by qualified refrigeration mechanics.
6. Maintain manufacturer's minimum recommended clearances, including distances to any plant material.

.02 Refrigerant Specialties

1. Installations shall be complete with filters, dryers, sight glass, and thermostatically controlled solenoid valve for pump down operation.
2. Provide isolation valves at all specialties.

.03  Refrigerant Piping

1. Refrigerant liquid and suction piping shall be type "L", hard drawn.
2. Joints shall be made by brazing at a temperature greater than 900 degrees Fahrenheit.  A nitrogen purge shall be maintained while brazing all joints.  Copper-to-copper joints and copper-to-brass joints shall be made with 15 percent silver brazing alloy.
3. Main piping fittings for driers, sight glasses, expansion valves, and controls should be flare type fittings, when available.
4. Refrigerant system should be evacuated to 500 microns held for at least 24 hours under this vacuum prior to charging the system with refrigerant.  The procedure must be witnessed by PSU representatives.
5. Double suction risers shall be employed on systems with capacity reduction and where required by lift.
6. Precharged lines are not acceptable for systems above 5 tons.
7. All refrigeration piping to be anchored with Hydra Zorb type anchors.
8. Refer to Details [23 xx xx .xx] and [23 xx xx .xx].  Details are not yet available in WEB-based manual.