The INVALCO CT (Control, Throttling) Series Flex Tube has been an industry standard in fluid level control for over five decades. A solid displacer hangs from a hollow flexure tube; as level changes, the tube flexes and a tangent rod moves a flapper over a nozzle in the pneumatic pilot, giving a throttling output to the control valve. With no rotating packing seals, knife edges, springs or float balls, set points stay stable, and the design is sensitive enough for liquid/liquid interfaces with small specific-gravity differences. Rotating the pilot 180° reverses the action.
Key specifications
Operating mode: Pneumatic throttling, direct or reverse
Process connections: Steel; male NPT, grooved, ANSI flange, ACME-thread hammer union
Working pressure: 0 to 1500 psi (by connection; grooved limited by coupling, 200 psi minimum)
Temperature: 250 °F with solid PVC displacers; 175 °F with sight glass or acrylic displacers (high-temperature aluminum displacers and Pyrex glass available)
Supply: 20-30 psi, 1/4" FNPT; output 1/4" FNPT; approx. 35 SCFH average at full bleed
Flexure tube: 304 SS
Enclosures: General purpose die-cast aluminum, or weatherproof molded fiberglass polyester with Lexan Margard window (vents exhaust to a safe area)
Options: Acrylic or Pyrex sight glass on hammer union models
How to specify / order (controls only; order displacer and nozzle separately). Add "-D" for the weatherproof enclosure.
Threaded: CTS-215, 2" MNPT, 1500 psi (80003490; -D 80003892)
Grooved: CTQ-402 4" (80003406; -D 80003578); CTQ-602 6" (80003408; -D 80003576), 200 psi
Flanged 2": CTF-202 150# (80003316), CTF-207 300# (80003317), CTF-214 600# (80003318)
Flanged 4": CTF-402 150# (80003303), CTF-407 300# (80003304), CTF-414 600# (80003305)
Flanged 6": CTF-602 150# (80003320), CTF-607 300# (80003321), CTF-614 600# (80003322); RTJ flanges consult factory
Hammer union, 1500 psi: CTU-415-A 4" (80003612); CTU-415-A-S 4" with sight glass (80003553); CTU-615-A 6" (80003614); CTU-615-A-S 6" with sight glass (80003605)
Displacer: choose vertical or horizontal, material (PVC, acrylic, aluminum, Synthane) and size from the bulletin displacer tables; standard kit is one 2-3/4" x 7" displacer; 4-1/2" or 5-1/8" discs recommended for oil/water interface
Hammer union nozzles: 4" x 6"/8"/12" (45016047/48/49); 6" x 6"/8.5"/10" (45003409/45003469/45003407)
Bulletin errors to note: the weatherproof part for the 2" 300# flanged model is printed as "CTF-407-D 80003589" (the same model code as the 4" 300# weatherproof unit, 80003585); the 4" Pyrex sight-glass model is printed as "CTU-615-A-A" (80003609) although it sits in the 4" row; the parts table is headed "6" 455 Valve"; and "Supply Pressure" is printed twice where the second entry is the 1/4" FNPT supply connection. Confirm these model and part numbers with the factory before ordering.
Pricing and lead time are quoted per configuration. Send the model code (or your application details), product, flow range, and pressure/temperature to Flow Measurement Services for a quote. Specifications summarized from Smith Meter (INVALCO) bulletin SSIN006 Rev 0.1 (8/17); confirm current data with the factory before ordering.
Smith Meter (formerly FMC Technologies / TechnipFMC Measurement Solutions), now manufactured by Guidant. Flow Measurement Services supplies and services Smith Meter equipment.