Viking Model F-1 Dry Pipe Valve, 3 in to 6 in, 175 psi

A latching differential dry pipe valve for unheated sprinkler systems

The Viking Model F-1 is a latching differential dry pipe valve that separates the water supply from a dry sprinkler system. A positive latching clapper and air plate assembly seals the air pressure in the piping, and the differential air-to-water seat design lets moderate air pressure hold back a much higher water pressure. When a sprinkler opens and the air pressure falls far enough to overcome the differential, the valve opens and water flows into the pipe. The datasheet gives an air-to-water pressure area differential of about 6 to 1 and says the valve has been available since 1993.

The valve also operates a water motor alarm and an electric pressure alarm switch. On large systems, or where faster action is needed, a Viking Model D-2 or E-1 accelerator can be added.

Technical specifications

Viking removed the LPCB, CE and VdS entries in the June 2023 edition, so check the current form if a project needs those marks.

Trim, accessories and installation

Viking sells the valve alone, as loose or modular trim packages without a valve, or pre-trimmed with conventional trim. Pre-trimmed part numbers carry a PT suffix, for example 07628PT for a 4 in flange by flange valve, and PTR adds pressure switches and an OS&Y supply control valve on the flange by groove 4 in and 6 in sizes. Accessories include the Model D-2 accelerator (09881), the E-1 accelerator with B-1 anti-flood device (08116) and the dry valve wrench and reset bar.

The valve must be trimmed to the Viking F-1 trim charts and installed vertically. Air or nitrogen must be clean, dry and oil free, automatic supplies must be regulated and restricted, and system pressure with the clapper closed must never exceed 60 psi (4.1 bar). Install it where freezing and physical damage cannot reach the valve, or inside a heated enclosure.

Related Viking valves

Compare them with other Fire Fighting equipment before choosing a valve for a new system.

Confirm before ordering

Confirm size, flange standard or grooved end, whether trim is needed, the supply pressure against the 175 psi rating, and the accelerator requirement. Fire protection valves are normally selected by the system designer to the project specification and local approvals. The attached Viking data lists all part numbers, dimensions and installation steps. Send the part number and quantity for a quotation.

How the Viking Model F-1 dry pipe valve works

A dry sprinkler system is filled with air, not water, so it can be used in rooms that may freeze. The F-1 valve keeps the water supply out of the pipes. A latched clapper holds back the water while a lower air pressure sits above it. When a sprinkler opens, the air escapes and the pressure drops. At a set point the valve opens and water flows into the pipe to the open sprinkler.

Where the Model F-1 is used

• Unheated warehouses
• Cold stores and loading docks
• Parking structures
• Outdoor canopies
• Any dry sprinkler system

Selection checklist for the Model F-1

• Valve size, 3, 4 or 6 in, or DN80, 100 or 150
• Flange by flange or flange by groove ends
• Water working pressure up to 175 psi
• Valve alone, loose trim or pre-trimmed
• Accelerator, Model D-2 or E-1
• Alarm devices, water motor and pressure switch
• Supply control valve type
• Space and weight

Installation, commissioning and maintenance notes for the Model F-1

Fit the valve upright in a heated room, with the trim connected as shown in the data sheet. Set the air pressure above the trip point as the instructions say. Test the alarms and trip the system with the main drain. Reset the valve after each trip and keep the room above freezing.

Requesting a quotation for the Viking Model F-1

Please send the size, the end type, the trim package and the quantity. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

Model F-1 pressure rating

The rated water working pressure is 175 psi, or 12.1 bar.

Model F-1 factory test

The factory hydrostatic test is 350 psi with the clapper open.

Model F-1 differential

The air to water pressure differential is about 6 to 1.

Model F-1 sizes

The sizes are 3, 4 and 6 in, and DN80, DN100 and DN150.

Model F-1 friction loss

The equivalent pipe length is 3 ft for 3 in, 5 ft for 4 in and 49 ft for 6 in.

Model F-1 weight

The shipping weight is 59 kg for the 3 and 4 in sizes and 89 kg for the 6 in size.

Model F-1 trim packages

Pre-trimmed part numbers carry a PT suffix. The PTR suffix adds pressure switches and an OS and Y supply control valve.

Valve records for the Model F-1

Record the air pressure, the trip test results and the dates of resets.

Choosing the right Model F-1 size

Choose the size from the system volume and the pipe size of the supply.