Watts LF909 Pequeno Serie Manual De Instalación página 4

Test Procedure for Reduced Pressure Assembly
Complete the following actions before starting the test procedures.
• Ensure all needle valves are closed on the test kit.
• Open test cock No. 4 and flush test cocks No. 1, No. 2, and No. 3 on the reduced pressure
assembly then close test cock No. 4.
• Attach the hoses as shown in the diagram. Bleed air from the kit then close the No. 2 shutoff.
Bleed Valve A
High
(red)
Low
(blue)
Test No. 1 - Check Valve No. 2
Purpose: To test check valve No. 2 for tightness against reverse
flow.
Requirements: The valve must be tight against reverse flow
under all pressure differentials.
1. Slowly open the needle valves "A" high (red) and "C"
bypass (yellow). Keep the needle valve "B" low (blue) closed.
2. Open test cock No. 4.
3. Observe that the pressure differential decreases slightly. If
the pressure differential continues to decrease (until the vent
opens), the No. 2 check valve is reported as "leaking."
Test No. 2 - Shutoff Valve No. 2
Purpose: To test shutoff valve No. 2 for tightness.
1. After passing Test No. 1, continue to test No. 2 by closing test
cock No. 2.
2. Observe that the pressure differential decreases slightly. If pres-
sure differential continues to decrease (approaching "zero"), the
No. 2 shutoff valve is reported to be "leaking."
NOTICE
A leaking No. 2 shutoff always gives a false reading in tests
No. 3 and 4.
Test No. 3 - Check Valve No. 1
Purpose: To test check valve No. 1 for tightness.
Requirements: The valve must be tight against reverse flow
under all pressure differentials.
1. Close needle valve A high (red) and open test cock No. 2.
2. Close test cock No. 4. Disconnect the bypass hose (yellow) at
test cock No. 4.
3. Open needle valves B low (blue) and C bypass (yellow), bleed-
ing to atmosphere. Then close needle valve B (blue) to restore
the system to a normal static condition.
4. Observe the pressure differential gauge. If there is a decrease
in the indicated value, the No. 1 check valve is reported as
"leaking."
4
Bleed Valve B
Bypass
(yellow)
LF909-QT-FS
Test No. 4 - Pressure Differential Relief Valve
Purpose: To test operation of pressure differential relief valve.
Requirements: The pressure differential relief valve must operate
to maintain the "zone" between the two check valves at least 2
psi less than the supply pressure.
1. Close needle valve C bypass (yellow).
2. Open needle valve A high (red).
3. Open needle valve B low (blue) very slowly until the differential
gauge needle starts to drop.
4. Hold the valve at this position and observe the gauge reading
at the moment the first discharge is noted from the relief valve.
Record this as the opening differential pressure of the relief
valve.
NOTICE
The differential gauge needle must drop slowly. This is
important to maintain stability.
5. Close test cocks No. 2 and No. 3. Remove the hoses from
test cocks No. 2 and No. 3.
6. Use the bypass hose (yellow) to relieve pressure from the test
kit by opening needle valves A, B, and C and bleeding valves
A and B.
7. Remove all test equipment and open No. 2 shutoff.
CAUTION
!
To prevent freezing, hold the test kit vertically to drain the
differential gauge and hoses before placing the kit in the case.
For additional testing information, refer to IS-TK-DL, IS-TK-9A,
IS-TK-99E, or IS-TK-99D.
No. 2 shutoff