Description; Installation - Pressure Tech LF-690 Operating And Service Manual

1. Description

The LF-690 is a single stage piston sensed pressure regulator, capable of a maximum 690 bar
inlet pressure. This can then be controlled to a range of outlet pressures depending upon
the sensing arrangement. As standard, the LF-690 comes with a Tungsten Carbide main
valve and heat treated 17-4ph seat, which provides excellent resistance to erosion on
hydraulic media.
Ceramic Ball and Plug options are available which provide ultimate protection against the
harsh service encountered on hydraulic systems with the Ceramic Plug design allowing the
LF-691 to achieve up to 1380 bar inlet*.
The regulator is also available with balanced main valve options which allow high accuracy
control of both low and high downstream pressures.
The housing has been machined from 316 SS (17-4ph SS on the LF-691 high pressure option)
to ensure maximum protection against the media on which it will be used, and the
environment in which it will be placed.
*achievable with specific modification – Please contact the office for information.

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 medium
pressure type (MP) 'A' and National Pipe Thread (NPT) 'N' options are available on this
regulator. 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.
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