Model PAF 450, 10″ Fill, Non-DOT Pressure Relief Device

Model PAF450 incorporates a 10” (254mm) reclosing pressure relief valve (PRV) mounted to weld-in 10” (254mm) collar. It includes a P/V normal vent. The PRV cover also serves as a quick open inspection hatch that incorporates a secondary safety catch.

The PAF450 was legal for installation on US DOT MC306 cargo tanks prior to August 31, 1998. Per 49CFR180.405(h)(2), a properly functioning PAF450 can be repaired and maintained but if the entire assembly needs to be replaced, it must be a PRV that meets the less-than 1 liter surge leakage requirement of 49CFR178.345(b)(3)(ii). Therefore, Model PAF450 is NOT permitted as a replacement on MC306 or DOT406 cargo tanks but can be installed on non-specification tanks or on tanks built and operated in countries where regulations permit. See Betts’ complete line of PAF406 and PAF306 PRV’s that meet requirements of less-than 1 liter surge leakage.

Product Details

Part NumberCollar MaterialStrongback and LatchPRV CoverNormal VentWeight
FVA9710BA*
FVA9710BS*
FVA9710CC*
FVA9710DD*
Aluminum
Steel
304 Stainless
316 Stainless
Steel Zinc-plated
Steel Zinc-plated
304 Stainless
304 Stainless
Aluminum
Aluminum
Aluminum
Aluminum
6238AL Aluminum
6238AL Aluminum
6238AL Aluminum
6238AL Aluminum
18.0 lbs (8.2 kg)
13.7 lbs (6.2 kg)
16.5 lbs (7.48 kg)
16.5 lbs (7.48 kg)
*Replace asterisk in part number to designate gasket material.

Example Assembly: FVA9710BAB

(10” PAF Pressure Relief Device, Zinc Steel Plated Strongback and Latch, Aluminum Collar + Black Nitrile Buna-N)
LetterGasket Material
BNitrile (Buna-N)
WWhite Hypalon
TPTFE (w/ Nitrile or Silicone Core)
VFKM Type A
  • Suffix “059” option for padlock loop installed in strongback.
  • Prefix “FSA” for both 6238AL normal vent & 6234AL inbreathing vent included.
  • Collar material should correspond with tank shell material. When welding collars to tank, care should be taken to insure collar remains flat and round with use of a welding fixture if necessary.

Technical Specifications

PAF450 Pressure Relief Valve6238AL Normal Vent (P/V Vent)
Set PressureRelated Air Flow Capacity
(Cubic feet per hour)
Pressure SetPressure Rated Flow CapacityVacuum SetVacuum Flow Capacity
Min 3.0 psig
(Min 20.7 kPa)
375,000 SCFH @ 5 psig
(10.618 SCMH @ 34.5 kPa)
Max 1.0 psig
(max 6.8 kPa)
1,750 SCFH @ 3 psig
(49 SCMH @ 20.7 kPa)
Max .375 psig
(Max 2.5 kPa)
3,350 SCFH @ 1 psig
(95 SCMH @ 6.8 kPa)