Smith Meter flow limiting valves are automatic, self-actuating, diaphragm-operated globe valves that limit maximum flow rate by sensing differential pressure across an integral orifice plate on the valve inlet. They are used mainly in systems with parallel meter runs, to protect the meters against excessive flow when fewer runs are operating. The 200-40A uses a normally-open 40A rate-of-flow pilot in the downstream side of the pilot loop and is typical for 2" to 4" valves; the 200-42A uses a normally-closed 42A pilot in the upstream side, which minimizes pressure drop when the valve is not throttling, and is used for 6". The limit is field-adjustable within the range set by the orifice plate size, product specific gravity and pilot spring.
Key specifications
Sizes / nominal flow: 2" 130 USGPM (492 L/min), Cv 50; 3" 420 USGPM (1,600 L/min), Cv 133; 4" 600 USGPM (2,250 L/min), Cv 204; 6" 1,000 USGPM (3,750 L/min), Cv 436
Models: 200-40A: 2", 3", 4"; 200-42A: 6"
Pressure rating: Class 150 ASME/ANSI, 285 psi (19.6 bar); Class 300, 300 psi (20.7 bar), based on -20 to 100 °F (derate above)
Maximum viscosity: 200 SSU (40 mPa·s); above that consult factory
Elastomers / temperature: Buna-N or LS Buna: -20 to 200 °F (-28 to 93 °C); Viton: -20 to 350 °F (-28 to 177 °C)
Materials: Model 202 cast steel main valve (stainless, carbon steel, ductile iron internals); 09SC strainer, Model 13 needle valve, 40A/42A pilot and 03A valve in carbon steel; carbon steel tubing (300 Series stainless optional)
Weight: 200-40A: 2" 47 lb (21 kg), 3" 84 lb (38 kg), 4" 137 lb (62 kg); 200-42A 6": 259 lb (117 kg)
Combinations: Back pressure, pressure reducing, check and thermal relief, solenoid block; for flow limiting plus solenoid block in any size the 40A-30A pilot configuration is recommended
Ordering information
The bulletin has no position-by-position model code. Per its ordering section, specify:
Valve size (200-40A for 2"-4", 200-42A for 6") and flange class
Liquid name and specific gravity or API gravity - critical to orifice plate sizing
Temperature range and viscosity range (minimum, normal, maximum)
Maximum working pressure and maximum flow rate setting
Seals: Low Swell Buna, Viton or Buna-N; any additional pilot functions
Bulletin notes: the 3" dimension E is printed 4.1 in (105 mm) here, while other 200 Series bulletins give 3.8 in (97 mm) for Class 150; The dimension table prints the 2" pilot-envelope dimension D as 7.5 in (140 mm); 7.5 in is about 191 mm.
Pricing and lead time are quoted per configuration. Send the model code (or the details above) with your product and operating conditions to Flow Measurement Services for a quote. Specifications summarized from Smith Meter bulletin SS03013 Rev 0.5 (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.