Siemens 91-HF Manual

INSTALLATION AND SERVICE INSTRUCTION
Siemens Industry, Inc.
UM91-HF
Rev 6
July 2012
Supersedes Rev 5
Model 91-HF
Filter Regulator
INTRODUCTION
The Model 91-HF Filter Regulator removes impurities from an air supply and delivers
an accurate output pressure.
SPECIFICATIONS
Port Size (In, Out and Gauge) ¼" NPT
Output Range 0-120 psig (0-800 kPa)
Max Supply Pressure 150 psig (1034 kPa)
Mounting Pipe or Through Body
Flow Capacity 22 SCFM (33.0 m3/hr) at 100 psig (700 kPa) supply with 20 psig (140 kPa) output
Exhaust Capacity 0.1 SCFM (0.17 m3/hr) with downstream pressure 5 psig (35 kPa) above set point
Sensitivity 1" (2.5 cm) of water
Air Consumption Less than 5 SCFM (0.17 m3/hr)
Effect of Supply
Pressure Variation Less than 0.2 psig (1.4 kPa) for 25 psi (170 kPa) change
Ambient Temp Limits 0° to 160°F (-18° to 71°C)
Weight 1.6 lb (725 g)
MATERIALS OF CONSTRUCTION
Body Diecast Aluminum Alloy, Irridite and Baked Epoxy Finish
Filter 3 Micron Phenolic Impregnated Cellulose
Diaphragm Nitrile Elastomer and Nylon Fabric
Valve Seat Plug Nitrile Elastomer
Additional Materials Brass, Zinc Plated Steel, Acetal
INSTALLATION
Install the regulator as close as possible to the instrument or tool it is to service. For best filter drainage, orient the drain
valve so that it is at the lowest point on the drip-well housing. The words “IN” and “OUT” are cast into the body to indicate
the direction of flow. See Specifications for port size. Installation dimensions are shown on the next page.

UM91-HF
Installation Dimensions
WARNING
As with any pneumatic device, excessive
pressure will eventually cause one or more
components to rupture. Such an event could
cause death or serious injury. To avoid this
possibility, the supply (IN) pressure must not
exceed 150 psig.
IMPORTANT
The Model 91-HF filter regulator has low capacity internal relief,
which provides very limited downstream over-pressure protection.
To avoid exceeding the output pressure limits in service, a pressure
relieving or pressure-limiting device should be provided.
INSTRUMENT AIR REQUIREMENTS
This product is intended for use in industrial compressed-air systems
only. Do not use this product where pressures and temperatures can
exceed those listed under Specifications.
CAUTION
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 an 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 an approval certificate.
CAUTION
Synthetic compressor lubricants in the instrument air may cause deterioration of some
components resulting in instrument failure. See materials of construction above.
The requirements for a quality instrument 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 maximum particle size in the air stream at the instrument should 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.
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UM91-HF
OPERATION
Prior to turning on supply air, back off the adjusting screw until there is no compression of the range spring; refer to
dimension and assembly drawings as needed. After turning the supply pressure on, turn the adjusting screw clockwise to
increase outlet pressure.
MAINTENANCE
1) To remove condensate, slowly open the drain valve and bleed accumulated liquid.
2) To clean the filter element:
a. Shut off supply air.
WARNING
Components can be ejected with great force if the instrument
is disassembled while pressure is applied. To avoid the risk
of death or serious injury, always turn off and vent supply
pressure and any downstream pressure source when
disassembling the instrument.
b. Drain condensate.
c. Remove four corner bolts from the bottom of the unit. Refer to the Assembly Drawing as needed.
d. Remove drip-well housing and filter.
e. Clean parts and reassemble in reverse order.
Assembly Drawing
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UM91-HF
3) To install replacement parts:
a. Order repair kits; see the assembly drawing for part numbers.
b. Shut off supply air. Back out the adjusting screw.
c. Remove four corner bolts from bottom of unit and four screws on the top. Remove all parts.
d. Replace all parts that show excessive wear.
e. Clean all parts and replace in the reverse order.
CUSTOMER/PRODUCT SUPPORT
For support and the location of your local Siemens representative, refer to the table below for the URL of the Process
Instrumentation (PI) portion of the Siemens public Internet site. Once at the site, click Support in the right column and then
Product Support. Next select the type of support desired: sales, technical (see the table below), documentation, or software.
Online Support Request http://www.siemens.com/automation/support-request
Technical Support 1-800-333-7421; 8 a.m. to 4:45 p.m. eastern time, Monday through Friday (except
holidays)
Customer Service & Returns 1-800-365-8766 (warranty and non-warranty)
Public Internet Site http://www.usa.siemens.com/pi
Technical Publications
in PDF Click the above link to go to the Siemens Internet site and then click Process Instrumentation. In the column to the right, click Support > Manuals. In the
column to the left, select the product line (e.g. Pressure or Temperature or
Controllers) to open navigation and search panes. Note: Navigation may change as
the site evolves.
Warranty
The sales contract contains the entire obligation of Siemens. The warranty contained in the contract
between the parties is the sole warranty of Siemens. Any statements continued herein do not create new
warranties or modify the existing warranty.
All product designations may be trademarks or product names of Siemens Industry, Inc. or other supplier companies whose use by third
parties for their own purposes could violate the rights of the owners.
Siemens Industry, Inc. assumes no liability for errors or omissions in this document or for the application and use of information in this
document. The information herein is subject to change without notice.
Procedures in this document have been reviewed for compliance with applicable approval agency requirements and are considered sound
practice. Neither Siemens Industry, Inc. nor these agencies are responsible for product uses not included in the approval certification(s) or
for repairs or modifications made by the user.
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