Tank Vents for Atmospheric Storage Tanks

A tank vent is the valve on top of an atmospheric tank that lets the tank breathe. Product goes in, vapor goes out. Product comes out, air comes in. If that valve is wrong, you pull a vacuum and collapse the shell, or you overpressure it. That is the whole job.

Linden Equipment is the US distributor for Sewon Q&TECH (SWQT) tank vents. We size them, we quote them, we ship them nationwide. You are not buying a catalog page. You are getting someone on the phone who will spec the vent for the tank you actually have.

Conservation vents / PVRV (Sewon SBF)

Sewon model SBF is the pressure/vacuum relief valve, the conservation vent. Pallet type, air-cushioned, FEP Teflon seats as standard. Full range of sizes and configurations from the factory. This is the day-to-day breather on the tank.

Emergency vents (Sewon SEA)

Sewon model SEA is the emergency vent cover. It stays closed in normal operation. It opens if the tank sees a fire case or another emergency load the conservation vent cannot pass. If you have a fire case on the data sheet, you need this conversation, not just an SBF.

Flame arresters (Sewon SFC / SFG)

Sewon SFC is the tank / vent-line flame arrester, 3/4 inch to 12 inch. Sewon SFG is the in-line / process-line unit, 1 inch to 40 inch. They stop a flame from traveling into the tank or down the pipe. End-of-line vs in-line is a spec choice. Tell us the piping and the vapor. We will not guess Group B vs Group D for you.

Sewon also builds a flame trap assembly (STA+SFH) for endurance burning on low-pressure lines, and a gauge hatch (SGH) if you need level, temperature, or sampling access without taking the vent apart. Ask if you need those. Do not order them because they look related.

Sewon is ISO 9001 and ATEX (94/9/EC) certified. Datasheets and the sizing program live on the OEM site. We will run the quote from your tank, not from a brochure.

What to send so we can quote

Call Rich at (847) 334-0704 or email info@lindenequipment.com. Have this ready:

• Tank diameter and height, or working volume
• Stored product
• MAWP / design pressure and vacuum
• In-breathing and out-breathing (pump rates, thermal)
• Fire case: yes or no
• Material (carbon steel, 304, 316, aluminum, other)
• Connection size and rating
• End-of-line or pipe-away
• Any flame arrester requirement

That is enough to size an SBF / SEA / SFC. If something is missing we will ask. We will not stall the quote waiting on a perfect data sheet.

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