VV34, 35 & 36 VACUUM BREAKERS
Vacuum breakers – also called vacuum venting valves or vacuum limiters - are valves which allow air to be aspirated once a set vacuum or pressure difference to atmosphere is reached. These valves are installed on pipelines, vessels, machines and equipment and are used, for instance, for venting tanks, limiting the vacuum in vacuum systems and protecting steam installations.
For control duties vacuum breakers may be used only to a limited degree. For such duties we recommend using the diaphragm-controlled vacuum control valve VV 33.
The VV 34 and VV 35 vacuum breakers have a tension spring and a spring cap complete with scale for setting the breaking pressure.
Under normal operating conditions the valve is kept closed by a pre-loaded spring and the internal vacuum acting on the valve cone. If the vacuum drops below the value set by means of the spring, the valve is opened by the atmospheric pressure and air enters the system. With increasing air flow the cone stroke and spring force increase. The pressure difference increases accordingly.
- These valves are no shut-off elements ensuring a tight closing of the
valve. In accordance with DIN EN 60534-4 and/or ANSI FCI 70-2 they
may feature a leakage rate in closed position in compliance with the
leakage classes III optional V:
- Leakage class III (metal sealing cone) = 0.1 % Kvs value
- Leakage class V (soft seal cone) = 1.8 x 10-5 x ?p x D* [l/h] *D=seat diameter
Please click HERE to view the VV34, VV35 & VV36 One Sheeter