Reliable DDX Deluge Valve, 2-8 in

Name: Reliable DDX Deluge Valve, 2-8 in | Seven Star LLC
Brand: Reliable Sprinkler
SKU: DDX

The Reliable DDX is a hydraulic piston (pushrod) operated mechanical deluge valve for systems where every discharge device is open and water must flow only when detection calls for it. Reliable describes a straight-through, low friction loss design with a latching clapper, offered with wet pilot, dry pilot or electric release trim. This page summarises Reliable Bulletin 519 (October 2026) so size, end connection, trim and approvals can be checked before requesting a quotation.

How the DDX deluge valve operates

Supply pressure in the side chamber acts on the pushrod and on the underside of the clapper; a lever multiplies the pushrod force and holds the clapper closed. When a releasing device opens and pushrod chamber pressure falls to about one third of supply pressure, the clapper lifts and the lever latches it open. Water then flows to the system and alarm outlet, and the valve is reset externally with the rear knob, without removing the face plate.

Key features from the bulletin

Straight-through waterway; Cv from 101 (2 in) to 1516 (8 in).
Intermediate chamber built into the seat.
Wet pilot, dry pilot (Model A with Model LP actuator) or electric release with a 175 psi or 300 psi solenoid valve.
Eight sizes from 2 in (50 mm) to 8 in (200 mm), grooved or flanged ends by size.

Technical specifications

Data from Bulletin 519 Tables A, E, F and G; ratings and listings vary by size as printed.

Size	Ends	End to end	Weight	Pressure	Listings
2 to 3 in, 76 mm	Groove x groove	12-1/2 in (318 mm)	34 lb (15 kg)	250 psi (17,2 bar)	cULus, FM, VdS
4 in (100 mm)	Groove x groove	14 in (356 mm)	64 lb (29 kg)	300 psi (20,7 bar)	cULus, FM, VdS, LPCB
4 in (100 mm)	Flange x flange	16 in (406 mm)	92 lb (42 kg)	300 psi (20,7 bar)	cULus, FM, VdS, LPCB
6 in (150 mm)	Groove x groove	16 in (406 mm)	95 lb (43 kg)	300 psi (20,7 bar)	cULus, FM, VdS, LPCB
6 in (150 mm)	Flange x flange	19 in (483 mm)	138 lb (69 kg)	300 psi (20,7 bar)	cULus, FM, VdS, LPCB
165 mm	Groove x groove	16 in (406 mm)	95 lb (43 kg)	300 psi (20,7 bar)	cULus, FM, VdS
8 in (200 mm)	Groove x groove	19-3/8 in (492 mm)	148 lb (67 kg)	250 psi (17,2 bar)	cULus, FM, VdS, LPCB

Parameter	Specification
End standards	Grooved ANSI/AWWA C606; flanged ASME B16.5 Class 150 or ISO 7005-2 PN16
Colour	Red
Trim weight (2 to 3 in / 4 to 8 in)	Wet 31 / 37 lb; dry 39 / 50 lb; electric 33 / 38 lb
Equivalent length C=120 (2 / 4 / 8 in)	4.4 / 14 / 53.5 ft
Temperature	Minimum 40 F (4 C); maximum 140 F (60 C)
Position	Vertical, water flowing up

Selection and ordering

Specify valve size, end configuration, operational trim and trim configuration (loose, segmentally assembled, or fully assembled with or without the water supply control valve), plus gauges of 0-300 psi or 0-600 psi. Sizes 2 to 3 in and 76 mm are grooved only. For dry pilot trims, minimum air or nitrogen pressure rises from 8 psi at 20 psi supply to 24 psi at 300 psi supply, and must never exceed 30 psi.

Installation notes

Install, test and maintain to NFPA 13 and the local authority. Heat tracing is not permitted and unauthorised trim changes may void the listing. Where heat may raise pushrod chamber pressure, fit pressure relief kit P/N 6503050001. Service kits: PN 6501200R03 (2 to 3 in) to R06 (8 in). Further procedures are in Technical Bulletin 520.

Typical applications

Deluge valves protect high-hazard areas such as hangars, fuel handling, transformer and turbine halls and petrochemical plant. Wet pilot suits freeze-protected areas, dry pilot suits unconditioned areas, and electric release suits panel-controlled detection. Confirm design basis and local approval before ordering.

Selection and installation notes

A fire protection valve is only one part of a sprinkler system, which must be designed, installed and commissioned by qualified people to the standard and the authority rules that apply to the project. Confirm the size, the pressure rating and the trim configuration against the design, install the valve in the position and orientation in the manual, fit the drain and alarm connections as drawn, test the alarm and the flow before handover and keep the inspection and test records. Check the listing and approvals needed for the project with the authority before purchase.

Before ordering, compare the ratings on the data sheet with the project specification, check the connection sizes and the supply conditions, and confirm which accessories, spares and documents travel with the unit. On delivery, inspect the packing, compare the nameplate with the order and keep the manual with the site records so that later commissioning and maintenance work can follow the maker instructions. Ask us if any detail is unclear and we will check it with the supplier before the order is placed.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Frequently asked questions

What sizes does the DDX come in?

2, 2-1/2, 3, 4, 6 and 8 in, plus 76 mm and 165 mm metric sizes.

Which release trims are available?

Wet pilot, dry pilot and electric release with a 175 or 300 psi solenoid.

What is the minimum installation temperature?

40 F (4 C); maximum ambient or water temperature is 140 F (60 C).

Can it be installed horizontally?

No. It must be vertical with water moving up through the valve.

Where is maintenance covered?

In Technical Bulletin 520; service kits are PN 6501200R03 to R06.

Sourcing Reliable Sprinkler equipment in Oman

Seven Star LLC is an independent supplier in Muscat that sources genuine Reliable Sprinkler products for contractors and facilities in Oman and the GCC. Each product page summarises the official bulletin for the model and links to the document, so teams can confirm ratings and part numbers before requesting a quotation.

Frequently Asked Questions