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Blow out all piping before connections are made to prevent the possibility of dirt or chips entering the relay. Use
pipe sealant sparingly, and then only on the male threads. A non-hardening sealant is strongly recommended.
Connect the relay to a source of clean, dry, oil-free instrument air. See Instrument Air Requirements below.
Pressure in excess of 100 psi to any connection may cause damage to the relay. In
any
event,
Instrument Air Requirements
Connect the relay to a source of clean, dry, oil-free instrument air. Failure to do so will increase the possibility of a
malfunction or a deviation from specified performance.
Use of process fluids other than instrument air is not recommended. No claim is made as to
the suitability of this product for use with other process fluids, such as hazardous gases,
except as listed on the appropriate certificate. Non-approved instruments are suitable for
use with instrument air only. Optional features and modifications such as tapped exhaust do
not imply suitability for use with hazardous gases except as listed on the approval
certificate.
Synthetic compressor lubricants in the air system at the instrument may cause the
instrument to fail.
There are many types of synthetic compressor lubricants. Some may not be compatible with materials used in
construction of the relay. Wetting of these materials with such an oil mist or oil vapor, etc., may cause them to
deteriorate and may ultimately result in the failure of the instrument. The following materials are in contact with the
supply air: aluminum, brass, neoprene, buna-N and stainless steel.
The requirements for a quality air supply can be found in the Instrument Society of America's "Quality Standard for
Instrument Air" (ISA-S7.3). Basically this standard calls for the following:
Particle Size – The particle size in the air stream at the instrument shall be no larger than 3 microns.
Dew Point – The dew point, at line pressure, should be at least 10°C (18°F) below the minimum temperature to
which any part of the instrument air system is exposed at any season of the year. Under no circumstances should
the dew point, at line pressure, exceed 2°C (35.6°F).
Oil Content – The maximum total oil or hydrocarbon content, exclusive of non-condensable, should not exceed 1
ppm under normal operating conditions.
MAINTENANCE
No lubrication of any sort is needed. The Parts List has spare and replacement part numbers.
Before disassembling the instrument, remove air pressure to the instrument.
When disassembling the instrument, make sure all parts are clean and free of dirt and debris. Reassembly is the
reverse order of disassembly. Make sure not to damage the O-ring(s) and diaphragm(s) when reassembling the
instrument.
CAUTION
maximum actuator pressure should never be exceeded.
CAUTION
CAUTION
CAUTION
3
SD61H-1
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