Flow Control Valves - FC Series- ¼" – 3"

1/4 GPM to 120 GPM

The Series "FC" flow controls are used to maintain a constant pre-determined flow in a system. They must be installed in the correct flow direction (indicated by label) to work properly. They utilize a diaphragm, which changes shape with inlet pressure changes, thus maintaining a constant flow rate. They are normally used to replace more costly flow control devices. Standard flow ranges are from 1/4 GPM to 120 GPM (.95 LPM to 454 LPM). The minimum pPom-fc.jpg (10806 bytes)ressure drop needed across the flow control is 15 PSI (1 Bar) in order to get the desired flow.

ACCURACY: The rated output of Series "FC" flow controls will vary ± 10% with Buna-N assemblies and ± 15% with EPDM assemblies.


  • Maintain constant flow with inlet pressure changes from 15 to 120 PSI (1 Bar to 8 Bars)
  • For corrosive and ultra pure liquid applications
  • No metals in contact with the liquid
  • Standard flow ranges from ¼ GPM to 120 GPM
  • Automatic in operation – no adjustments

MATERIAL OF CONSTRUCTION:  The standard Series "FC" flow controls are constructed of TYPE 1, GRADE 1 PVC (Polyvinyl Chloride) with diaphragms of either Buna-N or EPDM. Stainless steel fasteners are standard. Bodies are also available in virgin polypropylene, Teflon® , and Kynar® . Consult KTH Sales for details.


IMPORTANT:  These flow controls are designed for liquids similar in viscosity to water. All applications should be tested for flow characteristics and chemical compatibility to insure desired results. Swelling of the diaphragms in certain liquids will result in loss of flow rate accuracy. An in-line strainer or filter should be installed before the flow control when suspended solids are present, and for all applications below 1.0 GPM (3.8 LPM).

TEMPERATURE AND PRESSURE:  The Series "FC" flow controls can operate from 40° F (5° C - 60° C) with PVC bodies and either Buna-N or EPDM diaphragms. With optional polypropylene, Teflon® or Kynar® bodies they can operate from 40° F - 180° F (5° C - 82° C) with EPDM diaphragms, and 40° F - 160° F (5° C - 71° C) with Buna-N diaphragms. The Series "FC" flow controls must have at least 15 PSI 91 Bar) pressure drop across the control in order to deliver the rated flow. Maximum pressure is 120 PSI (8 Bars).

Series "FC" Pipe Size ¼" 3/8" ½" ¾" 1" 1-1/4" 1-1/2" 2" 3"
Basic Part Numbers FC025 FC037 FC050 FC075 FC100 FC125 FC150 FC200 FC300
Flow Rate Gal/Min ¼ - 2 ¼ - 2 ¼ - 2 3 – 24 5 – 24 9 – 40 25 – 64 41 – 120 65 - 120

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WWT Series - Flow control valves that use a fixed diameter orifice.  Designed for water service, these valves offer a high value for applications as rinse water control -- flows to 5.5 GPM.  ABS construction.   Contact us for details.

For applications that require changes in controlled flowrates consider rotometers.  Rotometers can include a metering or diaphragm valve for a manual setting of the rate.  For automated systems, a electronic flow controller would be matched to a valve actuator with a electronic positioner.   Contact us for details.