The Chemguard High Back-Pressure Foam Maker (CFM) is designed to produce expanded foam that is introduced into a cone roof storage tank by sub-surface injection. The sub-surface method should only be used on tanks containing standard hydrocarbon based fuels such as: diesel, kerosene, gasoline, etc. It is not suitable for use on tanks that contain alcohols or polar solvent type liquids that are miscible in water. The foam maker is normally installed in a dedicated fire protection line or the tank product line and is generally located outside the dike area that surrounds the storage tank. In accordance with NFPA 11 subsurface injection is not recommended for any tank having a floating roof.
The CFM is capable of producing expanded foam with an expansion ratio of between 2:1 to 4:1. It is designed to discharge expanded foam against a backpressure, which can be as high as 40% of the operating inlet pressure of the CFM. A minimum of 100-psi inlet pressure at the CFM is recommended for satisfactory operation.
The CFM is suitable for use with various types of foam solution generating devices. These include bladder tanks, balanced pressure foam pump proportioning systems, in-line balanced pressure proportioning units and foam pumper trucks. Unless high water pressure is readily available, in-line eductors are generally not suitable for use with sub-surface systems, because in-line eductors have a relatively high-pressure loss through the eductor. The residual pressure available on the discharge side of the eductor is often not high enough to ensure correct operation of the CFM and overcome friction loss in the piping and head pressure of the product stored within the storage tank.
FEATURES
- UL Listed
- Six standard sizes available to handle a wide range of flow requirements
- Compatible with AFFF, AR-AFFF and Fluoroprotein generated foam solutions
- Engineered to operate with a total back pressure up to 40% of the inlet pressure
- Manufactured in carbon steel with stainless steel air inlet screen and brass foam solution inlet orifice. Inlet orifice machined and sized to match desired flow rate and pressure
- Inlet and outlet 150 lb. raised face flanged fittings
OPTIONS
- CFM manufactured in brass
- 0-300 psi pressure gauge at inlet to CFM for monitoring of the foam solution inlet pressure
- Threaded inlet and outlets available on request
ORDERING INFORMATION
| Model |
Flow |
K-Factor |
**Inlet |
**Outlet |
Length |
| CFM 25-15 |
27 gpm @ 150 psi |
2.2 |
1 ½” |
1 ½” |
10” |
| *CFM 90-15 |
92 gpm @ 150 psi |
7.7 |
1 ½” |
1 ½” |
10” |
| *CFM 70-25 |
73 gpm @ 150 psi |
6.0 |
2 ½” |
2 ½” |
15” |
| *CFM 270-25 |
318 gpm @ 150 psi |
26.4 |
2 ½” |
2 ½” |
15” |
| *CFM 250-40 |
276 gpm @ 150 psi |
22.8 |
4” |
4” |
27” |
| *CFM 1000-40 |
1089 gpm @ 150 psi |
89.3 |
4” |
4” |
27” |
* U.L. Listed
** All flanges ANSI Class 150
