PRESSURE CONTROL
Vacuum breaker VV 34, 36
Vacuum breaker with setting scale

Technical Data

Description

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.
The standard version of the vacuum breakers is no equipment part with
safety function in accordance with the Pressure Equipment Directive. Otherwise this fact would be taken into account in the Declaration of Conformity.
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 5.1.
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.
The VV 34 vacuum breaker has a tension spring and a spring cap complete
with scale for setting the breaking pressure
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 compliance with leakage class IV (metallic seal 0,01% of
the Kvs value), optionally leakage class V (soft seal with Δp > 1 bar).

Standard

» VV 34 spring cap with setting scale
» All stainless steel construction

Options

» Soft seal
» VV 34 made of stainless steel / steel
» Leakage line connection for discharging the leakage in atmospere
» Special materials such as duplex, superduplex, HASTELLOY® or titanium, others on request
» Special connections:
ANSI or JIS flanges, other connections on request
» Special versions on request
Product

Technical specification

*Vacuum breakers should be selected according to the pressure difference
between the atmospheric pressure and the pressure inside the vessel or
pipeline, not according to the vacuum or absolute pressure in the vessel or
pipeline. All specifications given in data sheets or tables or on the scales of
valves etc. relate to this differential pressure.