DANIEL V707, Руководство пользователя

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SPRING LOADED BACK PRESSURE VALVE
9 Corrective maintenance
9.1 Control valve troubleshooting
Use the table below to troubleshoot the control valve. Contact the nearest Flow Lifecycle
Services center for assistance with repairs of Daniel products. It is important that servicing
be performed by trained and qualified service personnel.
Table 9-1: Troubleshooting issues of 707 Backpressure Control Valve
Condition Probable cause Correction
(1)
Valve will not open Upstream valve is
closed Open upstream valve.
Pump is not operating Start pump and check for cavitation.
Downstream valve is
closed Open downstream valve. (Check coupler on
bottom loading units and internal valve in
truck.)
Insufficient pressure Check pump. Check bypass and strainer located
in line.
Swollen O-rings Disassemble valve and replace O-rings. Check
compatibility of O-rings with product.
Valve opens too slowly Swollen O-rings Disassemble valve and replace O-rings. Check
compatibility of O-rings with product.
Valve will not close off
tightly Foreign material in
main valve piston seat Disassemble valve and inspect piston.
Swollen O-rings Disassemble valve and replace O-rings. Check
compatibility of O-rings with product.
Piston or seat O-ring
cut or defective Disassemble valve and replace if necessary.
(1) Refer to Mechanical disassembly procedures.
9.2 Verify the return to operational condition
Once corrective maintenance has taken place, verify that the control valve is working
properly by following the steps below.
Procedure
1. Inspect all bolts used to secure the control valve in-line to ensure that proper
mounting procedures have been followed and that flange connections are leak-
free.
2. Evaluate the system setup to ensure that all components are in the correct
operating sequence.
User manual Corrective maintenance
DAN-20064957 August 2019
User manual 55