Johnson Controls York YHAU-C, Installation, Operation And Maintenance Manual

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The outer flange of the disk holder has a plastic pipe stub supplied by the factory for shipping
purposes. The PLASTIC stub must be removed! Refer to Figure 10.
Rupture disk discharge piping material
ANSI/ASHRAE 15-2001 calls for the relief piping material to be compatible with the refrigerant in
the system. The refrigerant is deionized water that could exceed 200°F (93.3°C) in some cases. Use
schedule 40 steel pipe for the rupture disk discharge line material.
Rupture disk discharge piping construction
For the piping material, use carbon steel. The relief piping must be fabricated and constructed in
accordance with piping best practices. Follow any local codes (if applicable) governing the rupture
disk discharge relief piping. Due to the high temperatures of an absorption unit during operation,
and the expansion and contraction associated with this, the rupture disk vent piping must have a
flexible connection between the rupture disk outlet and the relief piping. The installing contractor
must supply the flexible connection and the relief piping.
Piping supports must be spaced according to the pipe material, size, and temperature.
Figure 10: Rupture disk set
LD29623
Plastic pipe and pipe stub Rupture disk clamp
Rupture disk
Note: Do not put any weight or moment arm forces on the flanges of the rupture disk.
Rupture disk discharge piping sizing
Ensure that the sizing of the rupture disk discharge piping is not less than the rupture disk
diameter. Where two or more relief devices are connected to a common line or header the effect of
back-pressure that develops when more than one relief device operates, must be considered. The
sizing of the discharge line for this condition must be based on the sum of each rupture disk outlet
area in addition to the pressure drop allowance through the outlet piping.
YHAU-C Single Effect Steam-Fired Absorption Chiller 30