8
■EPDT-179c■
(4)
Connect a primary pressure regulating valve or safety valve to the outlet side of the
pressure reducing valve to protect it and outlet side equipment.
※
Be sure to provide the protective valve to avoid system damage. (If the outlet pressure
reaches 100 kPa or higher, internal parts will be damaged and need replacement. :
Refer to Section 8.2 Troubleshooting.)
(5)
Be sure to attach a pressure gauge to the inlet and outlet of the pressure reducing valve.
※
Without pressure gauges, the pressure cannot be regulated correctly.
(6)
Connect stop valve and bypass pipe to the pressure reducing valve.
※
These are indispensable devices for maintenance and checking of the pressure
reducing valve. (Refer to Fig. 1 of 6.1 Example of piping diagram.)
(7)
The pressure reducing valve must be normal to the horizontal pipe, with the adjusting
spring side facing up. (Refer to Fig. 2.)
※
Otherwise, malfunction may occur and performance will be degraded.
(8)
The piping from the pressure reducing valve outlet must be of a size so that the current
flow velocity in the tube is 5-15 m/s.
※
Otherwise, malfunction may occur and performance will be degraded.
(9)
Be sure to connect the external sensing port to the outlet of the pressure reducing valve.
※
Otherwise, the outlet pressure is equal to that at the inlet.
Wrong connection may cause malfunction of the pressure reducing valve.
(10)
When two-stage pressure reduction is employed, the distance between the pressure
reducing valves must be 3 m or more.
※
A shorter distance may cause malfunction and the designed performance cannot be
obtained.
(11)
Do not install a quick opening/closing device e.g. solenoid valve at the inlet and outlet.
※
Fast open/close operation may cause malfunction and excessively shorten the valve
life.
(12)
Before installing the valve, verify the location of the inlet and outlet. The arrow on a side
of the pressure reducing valve indicates the direction of flow. Observe the arrow.
※
When installed in opposite direction, the pressure reducing valve cannot function as it
should.
(13)
Do not subject the pressure reducing valve to excessive load, deflection (bend), or
vibration, through the connected piping.
※
Any excessive physical disturbance may cause malfunction and excessively shorten
the valve life.
(14)
Secure the necessary maintenance space at the installation site of the pressure
reducing valve.
※
If the space is smaller than these values, the valve cannot be disassembled for
maintenance. (Refer to Fig. 2)
○
Space necessary for disassembly
Fig.2
