Tyco Star A-1 User Manual

Dry Pipe Valve
Model A-1, 4 Inch (DN100)
FlangexGroove
GENERAL DESCRIPTION
The Star 4 inch (DN100), Model A-1 Dry Pipe Valve is a
differential valve used to automatically control the flow of
water into a dry pipe fire protection sprinkler system upon
operation of one or more automatic sprinklers. The Model
A-1 Dry Pipe Valve also provides for actuation of fire
alarms upon system operation.
Dry pipe sprinkler systems are typically used in unheated
warehouses, parking garages, store windows, attic
spaces, loading docks, and other areas exposed to freez-
ing temperatures where water filled pipe cannot be util-
ized. When set for service, the dry pipe sprinkler system
is pressurized with air (nitrogen), and the loss of air pres-
sure through an operated automatic sprinkler, in re-
sponse to heat from a fire, permits the Model A-1 Dry
Pipe Valve to open and allow a flow of water into the sprin-
kler system piping.
The differential design of the Model A-1 Dry Pipe Valve is
such that the minimum air pressure in the piping is calcu-
lated to be approximately 1/5 of the static water supply
pressure plus an added safety factor that helps prevent a
false operation that might otherwise occur due to water
supply pressure fluctuations.
WARNING
The Model A-1 Dry Pipe Valve described herein must be
installed and maintained in compliance with this docu-
ment, as well as with the applicable standards of the Na-
tional Fire Protection Association, in addition to the stand-
ards of any other authorities having jurisdiction. Failure to
do so may impair the integrity of this device.
The owner is responsible for maintaining his fire protec-
tion system and devices in proper operating condition.
The installing contractor or sprinkler manufacturer should
be contacted relative to any questions.
TECHNICAL DATA
Approvals
UL and ULC Listed. FM and LPC Approved.
Working Water Pressure
20 to 175 psi (1.4 to 12.1 bar).
Friction Loss
Refer to Figure 3.
System Air Pressure Requirements
Refer to Table A.
Physical Characteristics
Body components illustrated in Figure 1 are constructed
of cast iron. The seat ring is copper, and the clapper is
ductile iron. The clapper facing is Buna-N.
OPERATION
The Model A-1 Dry Pipe Valves are differential type
valves that utilize a substantially lower system (air) pres-
sure than the supply (water) pressure to maintain the set
position shown in Figure 2-A. The differential nature of
the Model A-1 Dry Pipe Valve is based on the area differ-
ence between the air seat and the water seat. The differ-
ence is such that 1 psi (0.07 bar) of system air pressure
can hold approximately 5 psi (0.34 bar) of water supply
pressure.
The minimum system air pressure (Ref. Table A) is, there-
fore, calculated to be approximately 1/5 of the static water
supply pressure, plus a safety factor, to help prevent a
false operation that might otherwise occur due to water
supply pressure fluctuations.
Priming water within the body of the Model A-1 Dry Pipe
Valve, as shown in Figure 2-A, helps to maintain a tight
air seal at the air seat. Between the air and water seats,
an intermediate chamber is formed, and the intermediate
chamber is normally open to atmosphere through the
alarm port and piping to the Automatic Drain Valve
(5 - Fig. 4).
Having the intermediate chamber open to atmosphere is
critical to the Model A-1 Dry Pipe Valve remaining set,
otherwise the full resulting pressure of the system air
pressure on top of the Clapper Assembly cannot be real-
ized. For example, if the system air pressure is 40 psi
(2.7 bar) and there was 25 psi (1.7 bar) pressure
trapped in the intermediate chamber, the resulting pres-
sure across the top of the Clapper would be only 15 psi
(1.0 bar), which would be insufficient to hold the Clapper
Assembly closed against a water supply pressure of 100
psi (6.9 bar). It is for this reason that the plunger of the
Automatic Drain Valve needs to be depressed several
times during resetting of the Model A-1 Dry Pipe Valve,
414-570-5000 • 800-558-5236 • FAX 414-570-5010
2-00
2-2.1.31
STAR SPRINKLER INC.
www.starsprinkler.com
#1097 Valve
#1210 Trim
OBSOLETE

Tyco Star A-1 Specifications

General

Brand	Tyco
Model	Star A-1
Category	Control Unit
Language	English

Summary

General Description and Technical Data

Warning and Responsibility

Owner is responsible for maintaining the fire protection system and devices.

Approvals

Lists regulatory and industry approvals for the Model A-1 Dry Pipe Valve.

Working Water Pressure

Specifies the operational pressure range for the dry pipe valve.

System Air Pressure Requirements

Details the required system air pressure for valve operation.

Physical Characteristics

Describes the materials used for valve components like the body, seat ring, and clapper.

Operation and Valve Design

Differential Valve Principle

Explains the differential design and pressure relationship between air and water.

Intermediate Chamber Function

Details the function of the intermediate chamber and its connection to atmosphere.

Design Criteria

Installation and Temperature Requirements

Valve must be installed vertically and maintained above 40°F/4°C.

Heat Tracing Prohibition

Heat tracing is prohibited as it can cause mineral deposits and prevent proper operation.

Installation Configuration and Clearance

Provides installation configuration dimensions and inlet connection details.

NFPA 13 Compliance

Review NFPA 13 requirements for quick opening devices and alarms.

Installation Guidelines

Trim Installation Accuracy

Proper trim installation is critical for valve function and warranty.

General Installation Steps (1-6)

Covers cleaning parts, using sealant, ensuring flow direction, and drainage setup.

Further Installation Considerations

Air Supply and Test Connections

Covers air maintenance device and inspector's test connections.

Electrical and Hydrostatic Test Preparation

Details electrical connections and hydrostatic test preparation steps.

Setting Procedure

Initial Valve Setting and Draining

Covers closing valves, draining the system, and cleaning interior parts.

Reseating, Priming, and Pressurization

Details reseating the clapper, priming the valve, and pressurizing the system.

System Air Pressure and Leak Checks

Restores normal air pressure and checks for leaks via the automatic drain valve.

Recommended System Air Pressure

Provides a table for recommended minimum and maximum system air pressures.

Troubleshooting Leakage Issues

Advises on addressing water or air discharge from the automatic drain valve.

Final Checks and Notification

Ensures valve is set, opens main control valve, and notifies authorities.

Maintenance and Service Procedures

Inspection and Testing Recommendations

Recommends periodic inspections and tests for system integrity.

Notification Requirements for Testing

Advises notifying relevant parties before operational tests.

Permission for System Shutdown

Requires obtaining permission before shutting down the fire protection system.

Annual Operation Test Procedure

Outlines the procedure for performing an annual operational test of the valve.

Periodic Inspection Procedures

Annual Operation Verification

Details steps to verify valve operation annually.

Quarterly Waterflow Alarm Test

Procedure for testing waterflow alarms quarterly.

Weekly Pressure Inspections

Inspects water and air pressure gauges weekly.

Weekly Automatic Drain Valve Check

Checks the automatic drain valve for leaks by depressing its plunger.

Quarterly Priming Water Inspection

Inspects the priming water level quarterly.

Ordering and Warranty Information

Ordering Procedure

Specifies how to order the Model A-1 Dry Pipe Valve and associated trims.

Availability and Service

Information on product availability through distributors worldwide.

Limited Warranty

Details the one-year warranty period for defects in material and workmanship.