Smith Meter Model RB and UB Air Release Heads mount on Smith Meter air eliminators or strainers and release air or gas from petroleum liquids before they reach the meter. Both are float-operated mechanical heads with a 3/4"-14 NPT vent that must be piped to a safe point of discharge (never inside a building) with a flame arrestor and an open drip at the low point. The RB is the general-purpose head; the UB is the higher-pressure design. Petro-Gard style RB heads provide the air signal for Petro-gard block valves. The heads are NACE compliant.
Key specifications
Maximum working pressure: RB: 300 psig at 100 °F (285 psig for the vertical RB design); UB: 300 psig, or 720 psig version
Minimum product specific gravity: RB 0.50; UB (300 psig) 0.52; UB (720 psig) 0.57
Temperature: RB Buna-N or LS Buna -20 to 225 °F (-29 to 107 °C); RB/UB Viton 10 to 400 °F (-12 to 204 °C); UB Chemraz -20 to 500 °F (-29 to 260 °C)
RB materials: A105 carbon steel mounting plate, anodized aluminium seal block, stainless linkage, 304 SS float, A366 carbon steel float guard
UB materials: A216 WCB carbon steel mounting plate, A48 Class 30 cast iron distributor plate, stainless piston, 304 SS float, A366 float guard
Vent: 0.750-14 NPT; vent-rate chart given in the bulletin
How to read the model code
Example: R1 (RB head, Buna-N, 300 psig). Read the code left to right; each position selects one option:
00 (No head): NPT vent port (standard)
R1 / R2 / R3 (RB head): Buna-N (300 psig) / Viton (300 psig) / LS Buna
VR1 / VR2 / VR3 (RB head for VAR tank only): Buna-N (285 psig) / Viton (285 psig) / LS Buna
P1 / P2 (Petro-Gard style RB head): Buna-N / Viton
VP1 / VP2 (Petro-Gard style RB head, VAR tank only): Buna-N / Viton
U3 / U4 (UB head): Viton (300 psig) / Chemraz (300 psig)
Ordering information
These head codes are used inside the air eliminator and strainer model codes. Per the bulletin, specify:
Liquid name and specific gravity
Temperature range (minimum and maximum)
Maximum operating pressure (and CRN requirements for Canada)
The vessel the head mounts on (AR, VAR, strainer) and whether a Petro-Gard style head is needed
Bulletin notes: the head code list stops at U3/U4; the 720 psig UB codes (U1/U2) appear in the strainer and AR bulletins but not here; a temperature line ("RB, Low Swell Buna Seals") is misplaced inside the RB materials table. Eliminator head elbows (502932-001, 501994-001) and a BA eliminator head (536761-001) are listed separately on this store.
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 SS03040 Rev 0.5 (7/17); 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.