///Overpressure shutdown (pressure control valve)
Direct-drive plunger pumps

Overpressure shutdown (pressure control valve)

Direct-drive pumps use a pressure control valve (PCV) to dump excess flow.

Safety first: Switch off the pump, release all pressure (open the on/off valve or bleed-down valve) and lock out before you open any high-pressure part. Never put a hand or tool near a running jet.
1Check the causes, most likely first 0 of 3 checked
01Debris in PCV poppet/seat Most likely

The PCV cannot release and pressure rises.

How to check: Clean poppet and seat; replace if damaged.

PhotoArt. no.DescriptionReplaces OEMExcl. VAT
10262 Normally Open, Dump valve, 05069703
ValveKMT, Techni
KMT 05069703 € 898.80
10359 HP Adapter, N/O 3 Port Dump Valve, 49830904
Fitting & adapterKMT
KMT 49830904 € 48.00
10360 Dump Valve Assembly, 20427739
AssemblyKMT
KMT 20427739 € 1,052.40
11603 UHP Dump Valve Adapter, 20451557
Fitting & adapterKMT
KMT 20451557 € 140.40
12405 Pneumatic valve assembly, NO, UHP 90K, Dump valve, 2 port, 20468634
AssemblyKMT
KMT 20468634 € 1,258.80

02Control air pressure too high Possible

Too much air on the PCV.

How to check: Check control air (max ~2.8 bar on some models).

03Pressure transducer out of calibration Less likely

Wrong reading.

How to check: Calibrate the transducer.

Related problems

General advice based on manufacturer manuals and service practice. Always follow the manual of your machine. Not sure? .