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Ratio-Flow Controllers

Ratio-Flow Controllers

The Chemguard ratio flow controller is a device designed to meter the correct amount of Chemguard foam concentrate into the water stream over a wide range of flows and pressures with minimal pressure loss.  These devices are used in conjunction with either a bladder tank or a foam pump proportioning system.  Chemguard ratio flow controllers are UL Listed and FM Approved with certain Chemguard foam concentrates.  Typical applications include flammable liquid storage tanks, loading racks, aircraft hangars, and heliports or anywhere flammable liquids are used, stored, processed or transported.

The operating principle of the controller is based upon the use of a modified venturi.  As water passes through the inlet nozzle, pressure is reduced in the annular area of the nozzle.  This reduction allows the metering of foam concentrate into the water stream through a foam concentrate-metering orifice.

 

SPECIFICATIONS

Chemguard offers the ratio flow controller body in five models.  The 2-1/2” ratio flow controller is a threaded controller designed with a 2-1/2” female NPT threaded inlet and 2-1/2” male NPT threaded outlet.  The 3”, 4”, 6” and 8” ratio flow controllers are “between the flanges” units designed to fit between two ANSI 150 lb. pipe flanges. Only the recovery section protrudes into the system water piping.  To ensure a complete gasket seal when installing between flanges, each face of the controller is machined with 20 grooves per inch.

The ratio flow controller body is cast from ASTM 85-5-5-5 brass.  The inlet nozzle and metering orifice are machined from SAE #72 Brass.  The inlet nozzle set screws and metering orifice retaining ring are of stainless steel.

The inlet nozzle is secured by two stainless steel set screws.  This allows the nozzle to be removed from the controller for cleaning and/or repair.

Metering orifices are sized appropriately for each specified type and percentage foam concentrate.  A stainless steel retaining ring secures the metering orifice in place.

The controller body is clearly marked with a flow direction arrow and label to identify the type of foam concentrate and injection percentage ratio.

 

FLOW RANGE

The following table lists the nominal flow range for each size ratio controller.  The flow rates may vary when using other foam concentrates.  Please consult the Chemguard Engineering Department for specific applications.

SizeAR-AFFF
GPM (LPM)
AFFF
GPM (LPM)
2-1/2”130-400 (492-1514)40-400 (151-1514)
3”245-700 (927-2649)70-750 (264-2839)
4”400-1500 (1514-5678)200-1600 (757-6056)
6”960-3000 (3633-11356)300-3400 (1135-12870)
8”1510-4500 (5715-17034)500-5500 (1892-20819)

 

DESIGN INFORMATION

  1. To ensure correct operation of a ratio flow controller when used with a bladder tank, the pressure of the foam concentrate at the controller must be within 2 psi of the incoming water pressure.
  2. To ensure accurate proportioning over the flow range of the controller, minimum water inlet pressure of 30 psi must be available during operation of the system.
  3. Please review the controller dimension table for information on the minimum recommended length of straight pipe required upstream and downstream from the controller.

 

Technical Drawings

 

RATIO FLOW CONTROLLER DIMENSION TABLE

Ratio Flow Controller Size (Model)Dimensions
ABCD***EF
in.(cm.)in.(cm.)in.(cm.)in.in.(cm.)lb.(kg)
2-1/2” (CPC2.5)4.310.92.406.106.917.51 NPT123183.6
3” (CPC3.0)5.313.52.506.356.316.01-1/4 NPT1539125.4
4” (CPC4.0)6.817.32.756.998.020.31-1/2 NPT20512210.0
6” (CPC6.0)8.521.63.258.2612.431.52 NPT30773817.2
8” (CPC8.0)10.927.73.559.0212.431.52-1/2 NPT401027333.1

*** Straight pipe length required upstream and downstream.

SPECIAL INSTALLATION NOTE: 

A minimum of five (5) pipe diameters should be allowed at the inlet and outlet of the proportioner.

 

ORDERING INFORMATION

Foam Concentrate TypeRatio Flow Controller Part No.
2-1/2”3”4”6”8”
1% AFFF  EF10236 *EF10243 *EF10250  EF10257  EF10264
3% AFFF**EF10237**EF10244**EF10251**EF10258**EF10265
3% AR-AFFF**EF10238**EF10245**EF10252**EF10259**EF10266
6% AFFF  EF10239  EF10246  EF10253  EF10260  EF10267
3%/6% AR-AFFF @ 3% *EF10240 *EF10247 *EF10254 *EF10261  EF10268
3%/6% AR-AFFF @ 6% *EF10241 *EF10248 *EF10255 *EF10262  EF10269
2% High Expansion  EF10242  EF10249  EF10256  EF10263  EF10270
2% C2 (VEEFOAM) *EF10322 *EF10323 *EF10324 *EF10325  EF10326
3% FP  EF10518  EF10519  EF10520  EF10521  EF10522

* UL Listed
** UL Listed and FM Approved 
(Note:  For FM Approved unit, complete approved system purchase required, i.e. ratio flow controller, bladder tank, foam concentrate and discharge device.)