- View technical specifications
- What does this contain?
- Where are these required or used?
- How do I assemble this water motor gong?
What does this water motor gong assembly contain?
The Viking Model F-2 Water Motor Gong is a fire alarm bell that requires no electricity. This mechanical device sounds when water passes through the 3/4 in. NPT inlet, rotating a striker to produce a 90-decibel alarm.
This complete water motor gong assembly contains almost everything needed to sound an alarm just add pipes and fittings. Each Viking Model F-2 ships with:
- A motor assembly with a brass nozzle and a cast-iron housing
- A striker arm assembly featuring a stainless-steel arm, pin, and washer
- One 3/4 in. brass strainer for the alarm line
- One 16-3/4 in. stainless steel drive shaft
If the wall is less than 3 in. thick, this gong requires an extension mounting cup. If the wall ranges from 14 in. to 30 1/4 in. thick, an extension shaft is needed. Viking also offers a closure plate to protect gongs mounted on uneven walls against nesting birds and other intrusions. To place a special order for these components, call (888) 361-6662.
Where are these required/used?
Water motor alarms or electric fire alarm bells are required for any NFPA-13-compliant fire sprinkler system that has more than 20 sprinklers. Most often, Viking's #07862 Water Motor Gong works as a waterflow alarm. These alarms are typically placed on a building's exterior wall, and often guide firefighters to fire department connections (inlets used to supply water to a building's fire sprinkler system).
How do I assemble and install Viking's water motor alarm?
For a detailed look at this water motor gong's installation requirements, consult Viking's instruction manual.Typical assembly for the Model F-2 is as follows:
- Cut a hole no larger than 1 5/8 in. in the building's wall.
- Cut and thread a 3/4 in. galvanized spacer pipe (used to protect gong components). If Viking's extension mounting cup (sold separately) is used, cut the pipe 2 in. longer than the wall is thick. If no cup is used, cut the pipe 1 in. shorter than the wall is thick.
- Cut the drive shaft. If using an extension cup, make the shaft 5 3/4 in. longer than the wall's thickness. Otherwise, cut it 2 3/4 in. longer than the wall is thick.
- File the drive shaft to provide a 3/32 in. (2.4 mm) x 450 chamfer on both corners of both ends.
- Slide the spacer pipe over the shaft and thread the end of the spacer pipe into the gong support assembly coupling.
- Slide the closure plate (sold separately) against the gong's back. Secure with a 9/32 in. fastener if needed.
- Slide the free end of the space pipe into the hole of the support assembly.
- Slide the wall plate over the free end of the spacer pipe.
- Remove the thread protectors from the water motor and attach it to the spacer pipe.
- Attach the gong, flat washer, and label to the gong support with the included 12 in. screw.
- Connect the water motor inlet to the alarm outlet of a waterflow detection device. Install the 3/4 in. strainer on the line as close to the alarm outlet as possible.
Specifications
| SKU | Viking Part Number | Inlet Thread Connection |
|---|---|---|
| VKWMAF2 | 07862 | 3/4 in. (19.1 mm) NPT |
| Drain Thread Connection | Drive Shaft Length | Wall Thickness |
|---|---|---|
| 1 in. (25.4 mm) NPT | 16-3/4 in. (425 mm) | Up to 14 in. Thick |
| Sound Level at 10 Feet | Diameter | Optional Accessories |
|---|---|---|
| 90 dB | 8-1/16 in. Gong | Extra-Long Drive Shaft, Closure Plate, Extension Mounting Cup |
| Rated Working Pressure | Approvals/Listings | Availability |
|---|---|---|
| 250 PSI Water Working Pressure (WWP/CWP) | UL, CUL, FM, LPCB, CE, NYC 219-76-SA | Usually Ships Within 48 Hours |
