Venting Requirements for Poly Tanks
| Mechanical Pump Fill | Pneumatic Fill | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| IF ≤ 1,000 gallons | IF - Vent length ≤ 3' | IF - Vent length > 3' and ≤ 30' | IF - Scrubber application | ||||||
| ✔ Vent size should equal size of largest fill or discharge fitting | ✔ Maintain vent screen mesh size ≥ 1/4" or no screen used | ✔ 3 or less 90º elbows with no other restrictions or reduction in pipe size | ✔ Vent pipe size throughout scrubber system CANNOT be reduced! | ||||||
| ✔ Centerline of dispersion pipe not to be submersed > 6" | |||||||||
| IF > 1,000 gallons | ✔ Emergency Pressure Relief Cover Required IF > 1,000 gallons | ✔ Emergency Pressure Relief Cover Required IF > 1,000 gallons | ✔ Perforated dispersion pipe must be same diameter as vent or larger. Sum of perforations ≥ cross-sectional area of pipe | ||||||
| ✔ Vent size should exceed the largest fill or discharge fitting by 1" | |||||||||
| Tanker Discharge | Inlet/Fitting Size | Minimum Vent Size | Tanker Discharge | Inlet/Fitting Size | Minimum Vent Size | Tanker Discharge | Inlet/Fitting Size | Minimum Vent Size | |
| 2" | 2" | 4" | 2" | 2" | 6" | 2" | 2" | 6" | |
| 3" | 2" | 6" | 3" | 2" | 6" | 3" | 2" | 8" | |
| 3" | 3" | 6" | 3" | 3" | 8" | 3" | 3" | 10" | |
Click to see guidelines for vent placement.
Venting charts based on recommendation and criteria from Venting Design for ACFM Technical Paper.
