Hussmann Proto-Aire, Руководство по установке, Страница: 44 / 124

Protocol™ Installation and
Service Manual
REFRIGERATION PIPING
Important: Since Hussmann has no direct control over the installation,
providing freeze-burst protection is the responsibility of the
installing contractor.
Refer to Page 48
Always use a pressure regulator with a nitrogen tank. Do not exceed 2 pisg and
vent lines when brazing. Do not exceed 350 psig for leak testing high side. Do not
exceed 150 psig for leak testing low side.
Always recapture test charge in approved recovery vessel for recycling.
The Water Loop should be tested for leaks using pressurized water.
DO NOT exceed 75 psig at the lowest point in the piping.
Overview
This section details the major refrigeration components and their locations in each piping
system.
Refrigeration Line Piping
Use only clean, dehydrated, sealed refrigeration grade copper tubing. Use dry nitrogen in
the tubing during brazing to prevent the formation of copper oxide. All joints should be
made with silver alloy brazing material, and use 35% silver solder for dissimilar metals.
Liquid and suction lines must be free to expand and contract independently of each other.
Do not clamp or solder them together. Run supports must allow tubing to expand and
contract freely. Do not exceed 100 feet without a change of direction or an offset. Plan
proper pitching, expansion allowance, and P-traps at the base of all suction risers. Use long
radius elbows to reduce flow resistance and breakage. Avoid completely the use of 45°
elbows. Install service valves at several locations for ease of maintenance and reduction of
service costs. These must be UL approved for 450 psig minimum working pressure.
All Protocol™ units have one-inch drip pan at the bottom of the unit. DO NOT run piping
through the bottom of this pan.
Return Gas Superheat
Return gas superheat should be 10 to 30 °F on all units.
Suction Line
1. Install a downward slope in direction of flow. A P-trap is required for all vertical
risers.
2. Line may be reduced by one size after first third of case load and again after the
second third. Do not reduce below evaporator connection size.
3. Suction returns from evaporators must enter at the top of the line.
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