Daikin WCT, Инструкция по установке, эксплуатации и обслуживанию

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D-EIMWC01308-16EN - 26/40
Table 5, Relief Valve Data per Condenser Circuit
Condenser Code Pressure Setting
Min. Required Discharge Capacity
( lb-air/min )
C4224
200 psi 67
C4226
200 psi 72
C4824
200 psi 77
C4826
200 psi 83
C5424
200 psi 86
C5426 200 psi 94
Refrigerant Vent Piping
Codes require that relief valves be vented to the outside of a building, and this is a desirable practice for
all installations. Relief piping connections to the relief valves must have flexible connectors to minimize
strain, as well as vertical drop legs to retain condensation.
Remove plastic shipping plugs (if installed) from the inside of the valves prior to making pipe
connections. Whenever vent piping is installed, the lines must be run in accordance with local code
requirements. Where local codes do not apply, follow the latest issue of ANSI/ASHRAE Standard 15 code
recommendations.
Single Vent Line per Relief Valve
WCT units have relief valve settings of 200 psig and resultant valve discharge capacities of 75.5 lbm
air/min. Using the formulas in ASHRAE Standard 15 defines the maximum length of discharge vent
piping downstream of the pressure relief valve in Table 6.
The ASHRAE 15 User’s Manual provides that, when the length of vent pipe exceeds approximately 220
diameters ( Equivalent Length / Inside Diameter > 220 ), use 0.7848*(L)
0.2
(this equation is only true for
relief valve setting of 200 psig, relief valve discharge capacity of 75.5 lbm air/min and average friction
factor of 0.02) in order to compute the approximate internal diameter of the relief valve discharge line if
this diameter is constant for the entire length of pipe. Then compare the calculated internal diameter size
to the values in Table 6, and select a pipe having an inside diameter equivalent or bigger than the required
internal diameter using standard schedule 40 pipe.
Table 6 , Maximum Lengths of vent piping per relief valve vented to atmosphere .
Relief Valve Pressure Setting = 200 psig
Rated Relief Valve Capacity = 75.5 lbm air/ min
Nominal Pipe Size ( in ) 1-1/4 1-1/2 2 2.5 3 4 5
(I.D.) Internal Diameter of Pipe for Sch. 40
(Note 2)
( in )
1.380 1.610 2.067 2.469 3.068 4.026 5.047
(L) Equivalent Length of Discharge Piping (ft) 4 21 113 313 1,021 4,308 14,113
Notes:
1) This table is to be used only as a guideline for estimating and is subject to changes made in Standard ASHRAE 15
or overriding local code.
2) Sch 40 Pipe size used for an example only.