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1. Description
The LF-540 series are compact and economical high pressure regulators with precision
machined sensing elements to allow fine pressure control on pressures up to 414bar. The
LF-540 can be supplied as either non-venting or self venting (non captured / non
adjustable).
2. Installation
Before system start-up, it is recommended that all systems be pressure tested, leak tested
and purged with an inert gas such as nitrogen.
Prior to placing into service ensure that the regulator is in the fully closed position, with the
adjusting mechanism turned completely anti-clockwise.
Check the model number reference to ensure that the pressure range complies with the
installation requirements.
Visually inspect the regulator for any signs of damage or contamination. If any foreign
materials are present and cannot be removed from the regulator, or if the threads on the
regulator appear to be damaged, please contact the office immediately to arrange for the
regulator to be returned for service.
The Inlet and Outlet ports are clearly marked. Select the correct size and type of connection
fittings for these ports which are indicated in the regulators part number. Both British
Standard Pipe (BSPP) ‘B’ and National Pipe Thread (NPT) ‘N’ options are available on this
regulator. Use the correct dowty or bonded seal for BSPP connections, self centering seals
are recommended. For NPT threads, ensure that PTFE tape is applied correctly to the
fittings, applying two overlapping layers in the direction of the thread, taking care that the
tape does not come into contact with the first thread. Any gauge ports on the regulator will
be 1/4” NPT unless otherwise stated. If any gauge port is not required, ensure that the port
is plugged prior to installation.
The media supplied to the regulator must be clean. Contamination can damage the seat
which may cause the regulator to fail. Filtration suited to the application is recommended
upstream of the regulator. Should further assistance or information be required in relation
to installation of any Pressure Tech regulator please contact the office, giving reference to
the regulators part number and/or serial number.
3. Operation
Turning the adjusting mechanism clockwise compresses the spring, which in turn opens the
main valve and allows the inlet pressure to pass through the seat orifice until the outlet
pressure is equivalent to the loading forces set by the compressed spring. Increase the
outlet pressure in this way until the desired pressure is achieved. The desired outlet
pressure should be set whilst increasing the pressure. Do not exceed the maximum inlet and
outlet pressures of the regulator which are indicated on the regulator label.
