Pressure Control Valve - Complete Set

Complete unloader control piston assembly together with the pressure regulating knob. A ready-to-install set replacing the entire pump working-pressure regulation mechanism.

Application

The assembly handles working-pressure regulation and acts as the water circuit safety with the gun closed – when the trigger is released, excess water is redirected back into the low-pressure circuit instead of generating an uncontrolled pressure rise in the pump. The knob allows smooth adjustment of the working pressure value without dismantling the unit.

Symptoms – when to replace

• Working pressure cannot be adjusted with the knob, or it changes on its own during operation.
• Water leaking from the unloader housing near the knob or control piston.
• The pump jerks noticeably when the gun is closed or opened, despite sound plunger seals.
• The regulating knob is loose, sticks, or fails to transmit movement to the internal mechanism.

How to choose the right part

Selection is based on reference number 43444 – Kränzle uses different variants of this set depending on the series, so substituting a seemingly similar number (e.g. 40.490 or 43.444 1) can result in a mismatch despite close model kinship.

When ordering for quadro, pay particular attention: quadro 1200 TST uses the plain number 43444, while quadro 800 TST and 1000 TST use a different catalog number (43.444 1) – seemingly the same model family, but a different set.

[faq]

Does the same set fit the quadro 800 TST or 1000 TST, since they're the same large-quadro family?|No – these models use a different catalog number (43.444 1), despite being closely related to the quadro 1200 TST. Before ordering, confirm the exact model and compare with the removed part.

Does the working pressure need to be readjusted after replacing the assembly?|Yes, it's worth checking and, if needed, resetting the desired pressure value with the knob after fitting the new assembly, since the factory setting of the new part may differ slightly from the previous one.

How do I distinguish an unloader fault from a pump fault with similar symptoms (jerking, unstable pressure)?|It's worth observing when the symptom occurs – if the jerking happens exactly when opening/closing the gun, this points to the unloader. If uneven operation also occurs with the gun continuously open, the cause more often lies in the pump itself (plungers, valves).

Does removing this assembly require draining water from the system?|Yes, replacement requires depressurizing the high-pressure system – it's best to shut off the water supply and release pressure by opening the gun before starting disassembly.

[/faq]