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Minimum flow valve type Z1B-M - POLNA S.A.

Minimum flow valves are designed for use in recirculation systems of pumps supplying power boilers. They protect the pumps against hydraulic and thermal overload in case of low water consumption by the boiler, ensuring minimum flow in the bypass circuit of the pump (by-pass).

The valve type Z1B-M thanks to its construction, selection of materials and technology is a valve adapted to use in the most difficult working conditions, at a high pressure drop and risk of cavitation.

In the presented version, it can be used as a minimum flow valve in bypass systems (by-pass) of pumps supplying power boilers.

We can adjust the control valve to match your individual needs.

Nominal sizes: DN50, DN65, DN80, DN100
Nominal pressure: PN250, PN320
Connectionsfor welding ∅76x13,other types of connection – upon request
Leakage class:V class acc. to PN-EN 60534-4.
Direction of flow: above the plug
Flow rate:Kvs 7, 10, 16, 20
Characteristics: linear
  • high tightness of closing,
  • guaranteed external tightness, seals according to TA Luft regulations in the low pressure zone,
  • easy access to internal elements of the valve,
  • control or on-off function,
  • possibility to use pneumatic, hydraulic or electric drives,
  • wide range of designs, possibility to adapt the valve to individual customer requirements in terms of connections, flow parameters and others,
  • additional equipment: quick release valve for pneumatic actuators (quick opening), spring damper for hydraulic or electric actuators (flexible plug pressure to seat),
  • resistance to hydraulic impacts (water hammer),
  • high durability and reliability of operation.
Construction resistant to cavitation as a result of the use of multi-stage throttling, labyrinth (multipath) flow path and selection of appropriate materials, such as: full stellite for the plug and seat, titanium for valve stem, highly-hardened throttling cages, alloy cast steel for the body. It is also possible to adapt this solution for other reliable applications in passage or angle designs. <br/ >We can adjust construction (design) of control valve to your individual needs /examples/. In such cases, please contact our technical support specialist.


ul. Obozowa 23 Str
37-700 Przemyśl

TEL: +48 16 678 66 01
E-MAIL: sekretariat@polna.com.pl

KRS: NATIONAL COURT REGISTER: 0000090173 dated 12.02.2002 r. Provincial Court in Rzeszów, XII Division of National Court Register
COMPANY ID: 650009986     NIP: 795-020-07-05     BDO: 000030128
SHARE CAPITAL: 3.710.992,60 PLN
PAID CAPITAL: 3.710.992,60 PLN
BANK ACCOUNT NUMBER: 88 1030 1250 0000 0000 8901 4018 EUR SWIFT: CITIPLPX