USAutomatic Sprinkler Corporation asked Reliable Automatic Sprinkler’s David L. Asphlund, P.E., to teach a session for the quarterly workshop held April 21, 2006. David holds a Bachelor of Science in Mechanical Engineering from the University of Colorado and is a registered fire protection engineer. He sits on the NFSA Engineering and Standards Committee. David was a fire protection contractor for nineteen years and has been with Reliable Automatic Sprinkler Company, Inc. for ten years. Reliable’s Terry Rodeman, Midwest Regional Sales assisted David.

Reliable’s new Model DDX Valve features nine configurations. It can be trimmed for the following systems:

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Wet Pilot Deluge

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Dry Pilot Deluge

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Wet Pilot, Single Interlock Pre-action System

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Dry Pilot, Single Interlock Pre-action System

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Electric, Single Interlock Pre-action System

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Type D, Double Interlock Pre-action System

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Type F, Double Interlock Pre-action System

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Low Pressure Dry Pipe Valve

It is manufactured in four inch and six inch sizes with only one main drain. It is 250 psi, lightweight and grooved both ends. The system side check valve is not required. It has an external reset and no priming water is required. The DDX LP is used for dry systems and has the same low pressures as the LDX valve. The valve is hydrostatically tested with the clapper closed. The DDX is cULus Listed and FM Approved. Refer to Bulletins 510 (DDX) and 357 (LP Dry Pipe Valve System).

Included below are specifications for the DDX Deluge Valve and the DDX-LP Dry Pipe Valve:

Engineering Specification 4” (100 mm) and 6” (150 mm)
Model DDX Deluge Valve

Deluge valve shall be a [4” (100 mm)] [6” (150 mm)] [cULus Listed] [FM Approved] hydraulically operated, differential latching clapper-type valve. Deluge valve construction shall be of lightweight, ductile-iron construction with “drop in” bronze seat and clapper assembly. Bronze seat shall have O-ring seals to resist corrosion and leakage. Clapper facing shall be pressure actuated, providing a limited compression seat for the sealing force between the clapper rubber facing and the valve seat. Push-rod chamber shall be of a piston/push-rod design with diaphragm seal and have two ¼” vent holes for air/water leakage indication. Trip ratio shall be approximately a 3:1 force differential. Deluge valve shall be of the straight-through design to minimize friction loss, and be capable of being reset without having to remove the valve cover plate through the use of an external reset knob. Deluge valve shall be activated by [hydraulic wet-pilot] [pneumatic dry-pilot] [electric] actuation trim and deluge valve trim shall be galvanized. Inlet restriction orifice shall be factory installed into inlet port of deluge valve push-rod cover plate and not be a separate part of the deluge valve trim. End connection style to be [4” (100 mm) or 6” (150 mm) grooved inlet and grooved outlet, per ANSI/AWWA C606. Deluge valve shall have a rated working pressure of 250 psi (17.2 bar) and shall be factory hydrostatic tested at 500 psi (34.5 bar). Deluge valve to be [4” (100 mm)] [6” (150 mm)] Reliable Model DDX Deluge Valve (Bulletin 511).

Model DDX-LP Dry Pipe Valve System Specification

General Description

Dry pipe sprinkler system shall be a [cULus Listed] [FM Approved] low-pressure dry pipe valve system capable of providing a 17:1 water-to-air force differential. Dry pipe valve system shall consist of a lightweight, ductile-iron construction with “drop in” bronze seat, and clapper assembly utilizing an intermediate chamber design. Clapper facing shall be pressure actuated, providing a limited compression seat for the sealing force between the clapper rubber facing and the valve seat. Push-rod chamber shall be of a piston/push-rod design with diaphragm seal and have two ¼” vent holes for air/water leakage indication. Valve end connections shall be grooved outlets per ANSI/AWWA C606. Pneumatic actuation trim shall consist of all galvanized and brass trim, including associated pressure gauges, main drain valve, emergency release valve, and a low-pressure pneumatic actuator valve. The pneumatic actuator shall be cULus Listed/FM Approved for use with the dry pipe valve system. Dry pipe valve system air pressure shall only require between 10 and 22 psi (0.7 to 1.5 bar) for proper setting of the pneumatic actuator in accordance with the manufacturer’s instructions. Dry pipe valve shall be of the straight-through design to minimize friction loss, and be capable of being reset without having to remove the valve cover plate through the use of an external reset knob. Dry pipe valve shall actuate through the operation of the pneumatic actuator valve as a result of the loss of system air pressure caused by sprinkler activation. Pneumatic actuator shall be of cast iron construction with Buna-N diaphragm. Dry pipe valve system shall have a rated working pressure of 175 psi (12.1 bar). Low-pressure dry pipe valve system shall be Reliable [4” (100 mm)] [6” (150 mm)] Model DDX-LP, Bulletin 357.

Pneumatic Supply Pressure Options

Owner's Air Supply

Dry pipe valve system air pressure shall only require between 10 and 22 psi (0.7 to 1.5 bar) for proper setting of the pneumatic actuator in accordance with the manufacturer’s instructions. Air supply shall be provided by an owner supplied air system in conjunction with a [cULus Listed] [FM Approved] automatic pressure maintenance device, capable of maintaining a constant system pressure regardless of pressure fluctuations in the compressed air source. The pressure maintenance device shall consist of galvanized trim and brass parts, including a strainer and a field adjustable air pressure regulator, and have a working pressure rating of 175 psi (12.1 bar). The pressure regulator shall have an adjustable outlet pressure range of 5 to 50 psi (.34 to 3.4 bar). Pressure maintenance device shall be Reliable Model A-2.

Compressed Air Supply

Air supply shall be provided by an automatic tank-mounted air compressor sized for the capacity (volume) of the dry pipe system piping, and be capable of restoring normal air pressure in the system within 30 minutes. Dry pipe valve system air pressure shall only require between 10 and 22 psi (0.7 to 1.5 bar) for proper setting of the pneumatic actuator in accordance with the manufacturer’s instructions. Air supply shall be equipped with an automatic pressure maintenance device capable of maintaining a constant system pressure regardless of pressure fluctuations in the compressed air (or nitrogen) source. The pressure maintenance device shall consist of galvanized trim and brass parts, including a strainer and a field adjustable air pressure regulator, and have a working pressure rating of 175 psi (12.1 bar). The pressure regulator shall have an adjustable outlet pressure range of 5 to 50 psi (.34 to 3.4 bar). Pressure maintenance device shall be Reliable Model A-2.

Nitrogen

Nitrogen cylinders provided by an approved source shall provide the nitrogen supply. The nitrogen cylinder pressure shall be regulated and supervised through the use of a nitrogen regulating device and low-pressure trim kit. This device shall consist of a brass, single stage pressure regulator, equipped with high pressure inlet and low pressure outlet gauges, and ¼” copper connection tubing with galvanized ¾” x ¼” reducer bushing. Optional: Low-pressure trim kit shall be included to monitor the regulated nitrogen supply pressure to provide a low-pressure supervisory alarm. This kit shall include a low-pressure switch with associated galvanized connection trim. Assembly shall be a Reliable Nitrogen Regulating Device This device is to be used in conjunction with the Reliable Model A-2 pressure maintenance device.

Optional System Accessories

Accelerator

For system capacities greater than 500 gallons, an accelerator with associated galvanized trim kit shall be provided to exhaust air pressure from the pneumatic actuator trim piping in order to hasten operation of the dry pipe valve system. Minimum normal air pressure shall be 15 psi (1.0 bar) to ensure proper accelerator operation. Accelerator shall be [CULus Listed] [FM Approved] for use with the specific dry pipe valve system. Accelerator shall be capable of adjusting for small fluctuations in system air pressure without causing operation. The accelerator shall contain an integral Accelo-Check (anti-flooding) assembly to prevent entry of water and debris into critical internal areas during operation. Accelerator body and dome to be of cast aluminum and epoxy coated inside and out. Diaphragm construction to consist of Dupont Fairprene BN 5049 with stainless steel filter assembly. Trim kit shall consist of all galvanized and brass parts, including an isolating ball valve. Accelerator and trim kit shall be Reliable Model B-1 Accelerator Trim Kit for Model DDX-LP dry pipe valve system.

Water Flow Alarm Pressure Switch

Alarm pressure switch shall be provided to indicate water flow and provide a water flow alarm. Pressure switch shall be [cULus Listed] [FM Approved] and of the bellows activated type enclosed in a weatherproof, 4x, NEMA 4-rated enclosure incorporating tamper-resistant screws. There shall be two sets of SPDT (Form C) contacts rated at 10.0 A @ 125/250 VAC and 2.5 A @6/12/24 VDC. The pressure switch shall have a maximum service pressure rating of 250 psi (17.2 bar) and shall be factory adjusted to operate at a pressure of 4 to 8 psi (.27 to .55 bar) with adjustment up to 20 psi (1.3 bar). Switch shall be provided with a ½” NPT male pressure connection. Alarm pressure switch shall be System Sensor EPS 10-2.

High/Low Air Pressure Switch

A pressure supervisory alarm switch to monitor the reliability of the compressed air supply shall provide both a high and low-pressure supervisory alarm. Pressure switch shall be [cULus Listed] [FM Approved] and of the bellows-activated type enclosed in a weatherproof, 4x, NEMA 4-rated enclosure incorporating tamper-resistant screws. There shall be two sets of SPDT (Form C) contacts rated at 10.0 A @ 125/250 VAC and 2.5 A @6/12/24 VDC. The pressure switch shall have a maximum service pressure rating of 250 psi (17.2 bar) and an adjustable range of 10 to 100 psi (.7 to 6.9 bar), factory set to respond at 50 psi (3.5 bar) rising pressure and 30 psi (2.1 bar) at decreasing pressure. Switch shall be provided with a ½” NPT male pressure connection. High/Low pressure switch shall be System Sensor EPS 40-2.