SOR Weatherproof Low Range - Manual (Page 2)

2/8 Form 536 (08.13) ©SOR Inc.
Fh
FI
Fs
Fd
A
NC
NO
C
Failure to mount the housing on a fl at mounting surface may result in
torsional forces on the housing that could cause false trips or render the
pressure switch inoperative.
When mounting to an irregular or uneven surface, install rubber washers
on the bolts between the housing and the mounting surface (except in
high-vibration applications) to prevent housing deformation, which could
change the relative positions of internal parts and affect calibration or
render the device inoperative.
Installation
This type of differential pressure switch can be mounted in any position. Install low range
models in the same orientation that they are calibrated.
Weathertight Housing Attach the device to a suitable surface or pipe stanchion bracket
with two 1/4-inch diameter bolts. Line mounting by either process or electrical connection
is not recommended.
Explosion Proof Housing The TA housing must be attached with 2-inch U-bolts over the
housing hubs or two 1/4-inch diameter bolts. Line mounting by either process or electrical
connection is not recommended.
When Fh exceeds the combination of Fl and Fs, the piston (and piston shaft)
moves to actuate the electrical switching element.
There are only three wetted parts on
the Hi side process connection:
pressure port, diaphragm and o-ring.
The force-balance system
virtually eliminates friction
and resultant wear while
yielding excellent repeatability.
Series 20 Differential Pressure
Switches are well suited for a variety
of process applications. They are not intended for high-pressure fluid power (hydraulic)
applications where high-shock pressures and high-cycle rates are expected.
Safety Integrity Level (SIL) Installation Requirements
The SOR pressure switches have been evaluated as Type-A safety related hardware.
To meet the necessary installation requirements for the SIL system, the following
information must be utilized:
„ Proof Test Interval shall be one year.
„ Units may only be installed for use in Low Demand Mode.
„ Products have a HFT (Hardware Fault Tolerance) of 0, and were evaluated in a
1oo1 (one out of one) configuration. Form 1538 (03.12) ©2012 SOR Inc.