Frequently Asked Questions:
What Is Degassing?
Degassing is the controlled removal of dangerous vapors — including benzene, H₂S, 1,3-butadiene, chlorinated hydrocarbons, ammonia, VOCs, pyrophoric iron sulfide, and other toxic/flammable compounds — from tanks, vessels, spheres, pipelines, ships, barges, loading racks, vacuum trucks, landfills, and contaminated soil prior to entry, cleaning, inspection, or product change.
Envent captures these vapors and destroys them at >99.99% efficiency using mobile thermal oxidizers and scrubbers, delivering full compliance with EPA Benzene NESHAP/BWON, Refinery Sector Rule, MACT, state, and local air regulations.
Safer crew entry. Faster turnaround. Zero emissions risk.
Need degassing done right? Call 888-997-9465 or Request a Quote →
Hazardous & Regulated Vapors Safely Removed During Degassing
Envent’s mobile thermal oxidizers and scrubbers destroy >99.99% of the toughest compounds, including:
- Benzene & BTEX
- Hydrogen Sulfide (H₂S) – sour crude and high-H₂S streams
- 1,3-Butadiene
- Chlorinated Hydrocarbons (VCM, EDC, PCE, TCE, etc.)
- Ammonia & Ammonium Compounds
- VOCs (Volatile Organic Compounds)**
- LEL / Flammable Vapors
- Mercaptans & Reduced Sulfur Compounds (odor control)
- Pyrophoric Iron Sulfide (FeS)
- PFAS-related off-gassing (where present)
- All other Hazardous Air Pollutants (HAPs) listed under Benzene NESHAP, BWON, RSR, and MACT standards
One system. Every compound. Full regulatory compliance guaranteed.
Ready to eliminate these vapors safely and fast? Call 888-997-9465 or Request a Quote →
Where Degassing Is Required?
Envent provides rapid, compliant degassing for every confined space and vapor source in the industry, including:
- Above-ground storage tanks (crude, products, chemicals)
- Pressure vessels, spheres, and bullet tanks
- Distillation columns, reactors, and process towers
- Pipelines, pigging operations, and hydrostatic test vents
- Heat exchangers, drums, and separators
- Loading racks and terminal transfer systems
- Vacuum trucks and frac tanks
- Marine ships & barges (USCG-certified vapor control)
- Landfills, contaminated soil remediation, and railcars
From refinery turnarounds to emergency marine transfers — if it holds hydrocarbons or hazardous chemicals, we degas it safely and faster than anyone else.
Need it done tomorrow? Call 888-997-9465 or Request a Quote →
Does my degassing contractor truly understand the hazards of bringing the tank through the explosive range—and do they have engineered systems to eliminate that risk?
Managing the LEL explosive range is the most hazardous part of any degassing project. Your contractor must demonstrate deep technical knowledge and proven controls.
Have I verified the contractor’s actual experience level?
How long have they been performing tank and vessel degassing? Do I want them learning on my facility and on my dime?
Does my contractor have a formal grounding and bonding program?
Do they understand why assured grounding and bonding is essential to prevent static-related ignition hazards?
Does this contractor have numerous, verifiable references—or are they gaining “experience” at my expense?
High-risk operations should never be performed by inexperienced crews.
Is the contractor a true degassing specialist—or a “jack-of-all-trades, expert-at-none”?
Specialized systems, trained operators, and engineered controls matter. Generalists increase risk.
Does the degassing unit operator know how to properly calibrate instruments and maintain documentation?
A single missed calibration or skipped reading can force your environmental manager to report a violation or a Title V permit deviation.
Has the degassing or vapor control equipment been subjected to a full HAZOP (Hazard and Operability Study) by major oil companies?
Hazard-reviewed systems demonstrate a high level of engineering rigor and industry acceptance.
Does my contractor have a TRIR of 0.0 and an “A” rating in ISNetworld?
If not, why not? Their safety performance is a direct reflection of the risk they introduce to your site.
Is the contractor fully compliant with EPA, state, and local air-quality regulations?
Do they understand NSPS, NESHAP, MACT standards, benzene rules, regional air district requirements, and flare minimization regulations that directly affect degassing?
Will the contractor provide regulatory certifications and compliance documentation for my vapor control project?
Are they prepared to provide destruction efficiency data, source testing results, temperature logs, and written compliance confirmation required by EPA, state agencies, and local permitting authorities?
Does the contractor have the depth of equipment needed to size the system correctly for the application?
Do they have units ranging from 200 CFM to 5,000 CFM, and 1 MMBTU to 77 MMBTU so the system is properly matched to your tank, throughput, and vapor load?
Does unit size and burner capacity matter—or should I simply choose the lowest hourly rate?
Yes, it matters. Undersized equipment prolongs projects, increases emissions, and compromises safety.
Do flow rate (SCFM) and BTU/hr capacity really affect performance—or should I settle for IC engines and tiny thermal oxidizers?
Flow and BTU capacity are critical. Low-capacity units often cannot maintain required destruction efficiency or safe operating temperatures.
Why Choose Envent for Degassing?
Unlike general environmental contractors, Envent specializes exclusively in mobile vapor control and degassing, operating the largest and most advanced fleet in North America. Our systems support:
Tank degassing for refineries, terminals, and petrochemical plants
Vessel and barge degassing compliant with USCG 33 CFR 154 & 46 CFR 39
Pipeline evacuation and VOC destruction
Refinery MSS (Maintenance, Startup & Shutdown) compliance
High-flow thermal oxidizers engineered for rapid, safe depressurization
Every Envent system is engineered, permitted, and operated by trained experts—ensuring unmatched safety, speed, and regulatory compliance on every project.
