The “Big Mouth” Vent & Crossover Trap
Low Pressure Steam Service
VAC-25 PSIG PMO
Features
- Large Air Venting Capability
- Factory Calibrated & Tested
- Bronze Body, Forged Brass Cover, Union Nut & Tailpiece
- Pipe Sizes: 1/2” & 3/4” NPT (1/2” special order only)
- Piping Pattern: Vertical (Air Vent) or Horizontal for (Crossover Trap) application
- Designed for Steam Vapor and Low Pressure Steam Systems
Description
The Barnes & Jones “Big Mouth” vent is a thermostatic main vent designed for maximum evacuation of air and non-condensable gases from steam vapor systems and low-pressure steam heating systems operating at or below 1-2 PSIG. Available in ¾” NPT (standard) and ½” NPT (special order).For best results, install the vent approximately 8”-10”above the steam main piping and 12” from the end of the main. For systems operating at higher pressures the discharge should be connected to a dry return. The Big Mouth can used as a Cross-over steam trap when installed in the horizontal position and connected to a dry return.
| Capacity (CFM) Vent | ||||
|---|---|---|---|---|
| Model | Size | 1 oz. | 2 oz. | 3 oz. |
| BJ-2BM | 1/2” | 2.0 | 2.4 | 3.6 |
| BJ-3BM | 3/4” | 2.0 | 2.4 | 3.6 |
| Part | Materials |
|---|---|
| Cap | Brass, ASTM CDA-377 |
| Body | Brass, ASTM CDA-377 |
| Element | Stainless Steel |
| Gaskets | EPDM |
| Plug | Brass |
| Seat | Brass w/ Silicon O-ring |
| Capacity (EDR) Crossover Trap | |||||||
|---|---|---|---|---|---|---|---|
| Model | Pressure Differential (PSIG) | ||||||
| Type | Size | Orifice | .25 | .50 | 1 | 1.5 | 2.0 |
| BJ-2CR | 1/2” | 5/16” | 92 | 120 | 168 | 200 | 228 |
| BJ-3CR | 3/4” | 5/16” | 152 | 208 | 320 | 400 | 450 |
| Dimensions | |||||||
|---|---|---|---|---|---|---|---|
| Model | Size | A | B | C | D | E | Wt. # |
| BJ-BM | 1/2” & 3/4” | 3-3/16” | 1-1/8” | 2-1/2” | 3-1/16” | 4-1/2” | 2 |
| BJ-CR | 1/2” & 3/4” | 3-3/16” | 1-1/8” | 2-1/2” | 3-1/16” | 4-1/2” | 2 |
| Part | Part No. |
|---|---|
| Cap & Disc | BJC5842-BM |
| Nut | BJC346 |
| Tailpiece 1/2” | BJC544 |
| Tailpiece 3/4” | BJC1045 |
| O-ring | BJCS4870 |
Crossover Trap Application
P/N BJ-2CR & BJ-3CR
Angle Piping Pattern
Big Mouth Vent
P/N BJ-2BM & BJ-3BM
Vertical Piping Pattern
