Flare Knock-Out Drums
Flare knock-out drums are a specifically designed vessel used together with a flarestack system to “knock-out” or remove any liquids from the produced gas stream. Wellbore and facility gases are tied into and produced through the vessel, where the removal of liquid is completed by the use of bafflers and gravity. Upon removal, the produced fluid is drained off and disposed of.
Benoit Rentals Ltd. stocks new and used flare knock-out packages in a variety of sizes and orientations to suit a wide range of customer needs. Units are typically offered completely skidded, heated, packaged, and ready to be installed in field for short or long-term applications. We can design and custom-package most vessels to suit any specific application.
Flare Knock-Out
Our 5bbl flare knockouts are ready to be put into service and have options to make them work best for you.
Our 15 bbl flare knockouts are easy to set up and come with plenty of options to customize them to your needs.
Our 25bbl flare knockouts are ready to be put into service and have options to make them work best for you.
Our 50 bbl flare knockouts are easy to set up and come with plenty of options to customize them to your needs.
Proudly serving and renting equipment to the oil and gas industry in Alberta & Saskatchewan
We proudly service all of Alberta and Saskatchewan including Chauvin, Provost, Macklin, Wainwright, Hardisty, Camrose, Lloydminster, Vermillion, Bonnyville, Fort McMurray, Kindersley, Kerrobert, Edmonton, Calgary, Red Deer, Medicine Hat, Fort Saskatchewan, Nisku.
Feel free to stop in or contact us for further information regarding our equipment, and range of services in Alberta and Saskatchewan.
Alberta Oil and Gas
Rental Service Area
Saskatchewan Oil and Gas
Rental Service Area
Frequently Asked Questions
How do flare knock-out drums prevent burning liquid fallout and maintain AER Directive 060 compliance?
Operating without an adequately engineered knock-out drum violates Alberta Energy Regulator (AER) Directive 060 and Saskatchewan Directive S-01 flaring standards. When entrained liquids like produced water, light condensates, or fracturing chemicals bypass separation and enter the flare header, they cause severe smoking, flame instability, and hazardous burning liquid fallout—often called ‘flaming rain.’ Our skidded knock-out drums strip these fluids out before they reach the flare tip, ensuring clean, continuous combustion that prevents lease fires, soil contamination, and costly regulatory shut-in penalties.
How do I calculate whether a 5 bbl, 15 bbl, 25 bbl, or 50 bbl knock-out drum is required for my lease?
Selecting the right drum size depends on your anticipated gas flow rates, retention time, and the potential volume of sudden liquid slugs. While a compact 5bbl or 15bbl vessel is ideal for low-rate swabbing or steady sweet gas production, larger 25bbl and 50bbl vessels are required for aggressive multi-phase flowback, pipeline blowdowns, or wells prone to slugging. Sizing must ensure vapor velocity remains below the critical droplet dropout threshold, allowing liquids sufficient settling time to fall out of the gas stream before entering the flarestack line.
When should operators choose a horizontal knock-out vessel over a vertical vessel configuration?
The choice between horizontal and vertical knock-out vessels depends on available lease space and the nature of the produced fluid stream. Vertical vessels are compact, take up less lease footprint, and excel at handling high gas-to-liquid ratios with smaller condensate volumes. In contrast, horizontal vessels provide a substantially larger vapor-liquid disengagement surface area and higher liquid surge holding capacity. This makes horizontal packages the preferred choice for heavy emulsion testing, foaming fluids, or high-volume well cleanouts where large fluid surges occur unpredictably.
What winterization and heating systems protect knock-out vessels and dump valves from freezing?
East-central Alberta and Saskatchewan winters bring severe sub-zero temperatures that can freeze knock-out fluids, clog dump lines, and form dangerous hydrocarbon hydrates. To prevent operational freeze-offs, Benoit Rentals provides fully winterized knock-out packages equipped with catalytic Catadyne heaters, internal heating coils, or automated Burner Management Systems. Encased in insulated shelters or durable enclosures, these heating solutions ensure liquids remain warm and mobile, safeguarding automatic dump valves and level controllers against freezing during minus-40-degree cold snaps.
How do automated liquid level controls and high-level ESD switches prevent vessel overfilling?
To prevent vessel overfilling and accidental carryover into the flare stack, our knock-out drums are equipped with robust, fail-safe liquid level controls. We integrate pneumatic or electric liquid level controllers, mechanical sight glass gauges, and automatic liquid dump valves that discharge accumulated fluids into temporary storage. Furthermore, our units feature high-level shut-off switches (LSHH) that can tie into your emergency shutdown (ESD) system, instantly alerting operators or choking the well if liquid volumes exceed safe operational capacity.
Are your flare knock-out packages rated for sour gas (H2S) service and NACE MR0175 compliance?
When handling associated gas containing corrosive hydrogen sulfide (H2S), vessel metallurgy must prevent sulfide stress cracking and catastrophic rupture. Our sour-service flare knock-out packages are built in strict compliance with NACE MR0175/ISO 15156 standards and ASME Section VIII pressure vessel codes. Built with corrosion-resistant steels, post-weld heat treatment (PWHT), and sour-rated valving, our vessels safely isolate toxic, corrosive fluids, protecting lease personnel, nearby agricultural land, and local communities from hazardous sour gas releases.
How are knocked-out fluids drained, transferred, and stored on site without venting gas?
Once liquids are separated inside the knock-out drum, they must be safely evacuated without venting pressurized gas. Our skidded packages are outfitted with standardized flanged or threaded drain connections that easily tie into auxiliary fluid lines. Depending on your site configuration, fluids can be gravity-drained, dumped automatically into an adjacent 400bbl rental production tank, or transferred via automated skid-mounted pump packages. This continuous fluid management prevents vessel overfilling and simplifies vac-truck fluid hauling logistics on remote leases.
Can your knock-out drums handle abrasive sand cuts and high-energy fluid slugs during well cleanouts?
During drill stem testing, fracture flowback, or well workovers, the fluid stream often carries heavy abrasive sand, drilling mud, and volatile hydrocarbons that can erode internal vessel components. Benoit Rentals’ knock-out drums feature heavy-duty internal impingement baffles that absorb initial kinetic impact, dissipating gas velocity and capturing heavy particulates before they travel downstream. This rugged construction protects internal demister pads and downstream flaring equipment from premature wear, ensuring reliable performance even during aggressive, high-pressure well cleanouts.
What overpressure protection and certified pressure relief devices (PRVs) come standard on your units?
Every flare knock-out vessel operates as an essential pressure-containing boundary, requiring certified overpressure protection to safeguard field crews and surrounding infrastructure. Benoit Rentals supplies knock-out packages equipped with calibrated, ASME-stamped pressure relief valves (PRVs) and optional burst discs matched to your specific operational pressure limits. Our technicians inspect, test, and document all relief devices prior to delivery, ensuring your equipment meets all provincial occupational health and safety benchmarks and passes every third-party lease audit with complete peace of mind.
How does Benoit Rentals inspect and certify knock-out packages before dispatching to a lease?
Before any flare knock-out package leaves our Chauvin facility, it undergoes an exhaustive mechanical and quality-control inspection. Our certified shop technicians conduct ultrasonic wall-thickness testing, inspect all internal baffles and demister pads, test pneumatic dump valve actuation, and perform complete vessel cleaning to eliminate cross-contamination. Delivered via our dedicated in-house transport network directly to your lease in Chauvin, Wainwright, Macklin, or beyond, our skidded packages arrive fully certified, pre-plumbed, and ready for immediate tie-in.