The INVALCO Series 550 is a long nose adjustable choke used mainly in indirect heaters, and in any application that calls for a long nose choke design. The extended outlet of the angle-type body places the choke orifice inside the heater bath, so heat offsets the cooling of expanding high-pressure gas and minimizes hydrate formation and freeze-ups. Three orifice sizes are offered, each adjustable from full open to full closed in 1/64" graduations with a micrometer handwheel, a thumb-screw lock shoe to hold position and a safety bleed vent for maintenance personnel. It can be modified to meet NACE MR0175-2003.
Key specifications
Design: Long nose, angle-type body for indirect heater service
End connections: 2" XXH socket weld
Body / cover: Forged steel A-216 Grade WCB body; carbon steel cover
Maximum working pressure: 7,800 psi
Orifice sizes: 1/2", 3/4" and 1"; adjustable in 1/64" graduations
Trim: Hardened alloy or carbide stem/plug and seat
Packing: Non-lubricated Buna-N
Gas capacity (critical flow, 1000 psi): 6 / 14 / 15 MMSCF/day (1/2" / 3/4" / 1"); Cv 5 / 12 / 20
Options: NACE MR0175-2003 adaptable
How to specify / order
Model number and trim part number
Orifice size (1/2", 3/4" or 1")
Trim material (hardened alloy or carbide)
Upstream pressure and gas flow rate
NACE requirement
Spare parts needed (stem, seat, indicator dial, packing)
Pricing and lead time are quoted per configuration. Send the model, application details, product, flow range, and pressure/temperature to Flow Measurement Services for a quote. Specifications summarized from Guidant Measurement literature (Series 550 Choke Specifications); 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.