The Equipment That Keeps Fuel in the Tank and off the Ground
Every genset fueling point carries two built-in risks.
Pressure and vacuum swings inside a storage tank happen during liquid pumping, weather changes, temperature shifts, or vapor condensation. These swings may cause structural failure or rupture. Outside the tank the fill connection may drip and cause hazardous fuel spill.
A thief hatch handles the first risk, and a spill container handles the second. Together they cost a small fraction of the cleanup they prevent.
We’ve been manufacturing both at our Kansas City facility, along with the rest of our storage tank equipment line, for more than a century. If you spec fueling points for data centers, hospitals, industrial sites, or indeed any facility that runs standby generators, thief hatches and spill containers both belong on your standard detail.
If you’re putting that detail together now, our sales team can walk you through hatch sizes, patterns, and containment options for your tanks. Call 800 821-6583 or email sales@claybailey.com.
What a Thief Hatch Does at the Fueling Point
A “thief” is the sampling tool that operators lower into a tank, and a thief hatch is the tank-top hatch built to provide access for fuel sampling. The modern version does three jobs in one unit. It:
- Gives your team a gauging and sampling port.
- Seals vapor in during normal operation to control emissions.
- Relieves pressure or vacuum whenever either passes a set point.
The relief function is important on tanks. When vapor and liquid volume change, it puts stress on the tank structure. Tank relief thief hatches open just long enough to bring the tank pressure or vacuum back inside its design limits, then reseal, so the tank breathes only when it needs to.
Our thief hatch line includes round hatches in 8-inch and 20-inch sizes plus oval and long-pan patterns, so you can match the hatch to your existing tank opening.
Spill Containment Buckets Catch What the Hose Leaves Behind
The fill point has a simpler failure mode. Hoses drip when they’re disconnected, couplings weep, and a rushed delivery can overshoot the shutoff. A spill containment bucket surrounds the fill connection and catches those losses before they reach soil or tarmac.
On a standby fuel system, deliveries happen over and over for the life of the site. Containment at the fill point keeps these safe and uneventful, and it gives your delivery drivers a forgiving target to work over.
The Right Thief Hatch Pays for Itself
Federal and state spill prevention rules apply to facilities that store fuel, and diesel on the ground brings cleanup costs, lost product, and regulatory attention all at once. Set that against the price of outfitting a fueling point properly, and tank thief hatches and spill containment buckets are among the least expensive items on a fuel system bill of materials.
During an outage, the whole facility leans on that fuel system, and a thief hatch that has held its seal through years of pressure cycles is an important part of keeping that fuel system working as it should.
To price that protection into a project, send your tank opening sizes and fill point details to our sales team at sales@claybailey.com, and we’ll help you match the right models.
Evaluating Thief Hatch Manufacturers
Plenty of thief hatch manufacturers can quote you a catalog number, but not so many stand behind the hatch for the life of the tank.
Build quality is the first separator. We cast, machine, and finish our equipment in-house, which keeps the tolerances that hold a seal tight under our control.
Compliance standards come next. Our storage tank line is built to UL compliance standards and to support EPA and OSHA requirements, so the paperwork behind the product holds up when your project gets reviewed.
Domestic manufacturing matters here too. Our Kansas City operation dates to 1913, giving you a nearby, accountable source when availability affects the project schedule.
The last thing to ask thief hatch manufacturers is what happens when your project doesn’t fit the catalog. Real fuel systems bring odd opening sizes and unusual configurations, but you can send those details to our custom product development team, which develops and produces tank thief hatches and related equipment within the same facility.
Spec Every Fueling Point With the Right Thief Hatch
Once tank relief thief hatches and spill containers are on your standard fueling point detail, every site you build automatically gets the protection it needs.
Browse our full line of thief hatch models to match sizes and patterns to your tanks. To talk through a spec or request product details, call our sales team at (800) 821-6583 or email sales@claybailey.com. You can also send us a message online, and we’ll follow up with the documentation your project needs.