Self-acting back pressure regulators are simple control valves offering
accurate control while being easy to install and maintain. They control
the pressure upstream of the valve without requiring pneumatic or
electrical control elements.
The UV 3.5, UV 3.5S and UV 3.5Z backpressure regulators are
spring-loaded diaphragm-controlled proportional control valves for
small volumes. They are manufactured from deep-drawn stainless steel
featuring excellent corrosion resistance. The valve cone can be fitted
with a metallic or soft seal.
The spring module comprising spring cap, spring, adjusting screw,
diaphragm and internal components, is connected to the valve body only
by means of a clamp ring and two bolts. Changing the diaphragm or the
complete spring assembly for a different control pressure range is
extremely simple and does not call for special tools. The same applies to
servicing and maintenance.
Changing the control pressure setting does not affect the height of the
valve (non rising adjusting screw).
The inlet pressure to be controlled is balanced across the valve seat by
the force of the valve spring (set pressure). If the inlet pressure rises
above the set pressure, the valve opens. With decreasing inlet pressure
the valve control orifice reduces, when the pipeline is depressurised, the
valve is closed. Rotating the adjusting screw clockwise increases the inlet
pressure.
The UV 3.5S and UV 3.5Z overflow valves require a pilot line (to be
installed on-site).
These valves are no shut-off elements ensuring a tight closing of the
valve.