WandfluhBVTPM22-B-200EU Type-Tested Hydraulic Safety Relief Valve — Pilot Operated Screw-In Cartridge, 200 bar Set, M22x1.5 ISO 7789, 30 l/min, Factory Sealed

Product Description

What this part is:
A Wandfluh BVTPM22 pilot-operated pressure relief valve in screw-in cartridge form, factory set to a 200 bar response pressure. It is a certified safety valve: designed to AD-2000 and EU type-tested in accordance with the Pressure Equipment Directive 2014/68/EU. The steel cartridge body and cover are zinc coated for corrosion protection and the setting is secured with a blue plastic lead seal.

A type-approved safety valve protects a circuit against overpressure, carries a PED type examination, and arrives factory set and sealed. That is a different class of device from an operator-adjustable pressure control valve, and on a pressure system requiring certification it is specified by that certification. Wandfluh AG is a Swiss hydraulics manufacturer based in Frutigen.

Decoding the order code:
The Wandfluh type code reads BVT PM22 – [range] – [pressure] #[index].

BVT: pilot-operated pressure relief valve, EU type-tested to PED 2014/68/EU.

PM22: screw-in cartridge with an M22x1.5 thread for a cavity to ISO 7789, specifically ISO 7789-22-02-0-98.

B: the response pressure range band. Wandfluh’s bands are A = 50 to under 160 bar, B = 160 to under 260 bar, C = 260 to 350 bar. This cartridge is built with the mid-range spring set.

200: the response pressure in bar, which sits correctly inside the B band. Standard preferential settings are 100, 140, 250, 330 and 350 bar, and any value from 50 to 350 bar can be specified, so a 200 bar unit is a made-to-order setting rather than a shelf standard.

#: the design index, applied by the factory.

Additional markings: ETO880, 593.3175, 1733400180 and 11.17 are OEM, order and date markings carried with the part rather than Wandfluh type-code fields, and are kept here as search terms. 11.17 most plausibly reads as a November 2017 date code.

The three pressures that define a safety valve:
This is the part of the specification most people skip, and on a certified relief valve it is the part that determines whether the circuit actually stays protected.

Response pressure: 200 bar, per the type code, with a tolerance of ±3 %.

Blow-off pressure: a maximum of 10 % above the response pressure, so this valve may be passing full flow at up to roughly 220 bar.

Closing pressure: a maximum of 15 % below the response pressure, roughly 170 bar.

Read those together. A circuit’s maximum working pressure must sit below the closing pressure, or the valve will chatter and never fully reseat; components and hoses must be rated above the blow-off pressure, not just above the 200 bar set point. A design that treats 200 bar as both the working pressure and the protection point gives a permanently weeping relief valve and a maintenance team convinced the valve is faulty.

Published specifications:
Construction: pilot-operated pressure relief valve, screw-in cartridge for a cavity to ISO 7789.

Mounting thread: M22x1.5; fastening torque MD = 50 Nm.

Mounting position: any.

Maximum flow: Qmax = 30 l/min.

Maximum nominal pressure: pN max = 350 bar.

Response pressure of this unit: 200 bar (band B, 160 to under 260 bar), tolerance ±3 %.

Ambient temperature: −20 to +50 °C.

Fluid temperature, standard: −20 to +70 °C.

Hydraulic fluid: mineral oils of fluid group 2; other media on request.

Viscosity range: 12 mm²/s to 320 mm²/s.

Maximum permissible contamination: ISO 4406:1999 class 18/16/13, recommended filtration β 6…10 ≥ 75.

Weight: 0.20 kg.

Seals: O-ring ID 14.00 x 1.78 (Wandfluh 160.2140), O-ring ID 18.77 x 1.78 (160.2188), back-up ring RD 14.6 x 17.5 x 1.4 (049.3177).

Mounting data:
Flow path: the valve relieves from port P (1) to tank line T (2).

Tank-line back pressure: must not exceed 3 bar at Qmax. Wandfluh states this explicitly. Pilot-operated relief valves add tank-line back pressure to the effective setting, so a restricted or shared return line raises the pressure at which the circuit is actually protected.

Block material: Wandfluh states that the hydraulic block material is chosen by the user in accordance with the PED, and recommends steel with a tensile strength of at least 330 N/mm² for pressures above 160 bar. At 200 bar, that recommendation applies to this installation.

Cavity: stepped cavity to ISO 7789-22-02-0-98; Wandfluh cavity data sheet 2.13-1003.

Hazardous-area use:
Wandfluh publishes ATEX fluid-temperature limits for this cartridge. For ATEX IIC, T6 the permissible fluid temperature is −20 to +40 °C, and for ATEX IIC, T4 it is −20 to +70 °C. A T6 classification therefore costs 30 °C of fluid temperature headroom; on a system that runs hot and needs T6, the oil temperature has to be controlled to suit, which is a cooler-sizing decision made at design time rather than a valve decision.

Quantity and configuration:
One cartridge, factory set and lead-sealed. The hydraulic manifold block, any line-mount body, sandwich or flange plate, and the stepped cavity tools needed to machine an ISO 7789 receptacle in steel or aluminium are each separate items; Wandfluh hires or sells the cavity tools. The setting is secured by the blue lead seal, which is what carries the type approval with the valve.

Interchange guidance:
Search forms include BVTPM22-B-200, BVTPM22B200, BVTPM22 B 200, BVT-PM22-B-200, BVTPM22, ETO880, 593.3175 and 1733400180. Related Wandfluh M22x1.5 cartridges: BVPPM22 (proportional pressure relief, solenoid adjusted, Qmax 100 l/min, pmax 400 bar), BVBPM22 (proportional, explosion-proof Ex d IIC, for hazardous areas and mining) and BVPPM22_ME (proportional with integrated electronics, analogue or CANopen / J1939 / Profibus DP). Those are proportional valves whose setting is commanded electrically, and they occupy a different role from a sealed, type-tested safety valve on a PED-regulated system, however similar the cavity and flow figures look.