HEMRUNK Transfer Tank Vented Fuel Cap 2" NPT Threaded — Iron Base, Spring-Loaded Vent & Leak-Resistant Seals

HEMRUNK transfer tank vented fuel cap is a replacement 2" NPT threaded diesel tank cap that vents pressure and prevents leaks while allowing air into the tank.

This heavy-duty replacement cap fits transfer tanks and auxiliary diesel tanks that accept a 2" NPT threaded neck. Built to match common transfer-tank standards, the HEMRUNK cap combines a threaded iron base, internal seals and a spring-loaded vent mechanism to manage tank pressure and protect fuel integrity during transport and storage.

How does this vented cap protect my transfer tank during filling and transport?

The vent relieves excess pressure that can build up inside a sealed transfer tank when temperatures change or fuel is added quickly. By allowing controlled airflow, it reduces the chance of tank deformation and minimizes stress on seams and fittings.

• Spring-loaded vent opens to release built-up pressure.
• Seals and gaskets prevent liquid fuel from escaping while venting air.
• 2" NPT threaded iron base ensures a tight mechanical fit to the tank neck.

Will this cap stop fuel leaks and keep contaminants out?

Yes — the HEMRUNK cap uses internal seals and a snug iron base to block liquid flow while the venting function remains active for air exchange. The design helps keep dirt and water from entering the tank when the cap is properly seated and locked in place.

• Multiple sealing surfaces reduce risk of seepage in normal conditions.
• Robust iron base provides a secure mechanical connection to the tank thread.
• Vent mechanism prevents vacuum formation without exposing fuel to contaminants when closed.

How simple is installation and removal for routine service?

Installation requires no special tools: align the cap lip with the neck groove, press down and rotate clockwise until it seats. Removal follows the reverse motion—press down and rotate counterclockwise—making it quick to access the tank for refueling or inspection.

• Tool-free, twist-on installation for fast replacement of common transfer tank caps.
• Clear tactile engagement when the cap is fully seated to ensure secure fitment.
• Durable construction withstands repeated service cycles without thread damage.

What tanks and applications is this cap compatible with?

The cap is engineered for use on transfer tanks, mobile fuel tanks, diesel tanks, auxiliary tanks and some Weather Guard-style tanks that accept a 2" NPT threaded neck. It serves fleet, agricultural, construction and mobile fueling needs where a vented, leak-resistant cap is desirable.

• Compatible with most transfer and auxiliary diesel tanks using 2" NPT thread.
• Suitable for mobile fueling rigs, service vehicles and equipment tanks.
• Designed as a replacement for popular transfer-tank caps with similar configurations.

Who is this cap for? Installers, fleet managers, farmers and contractors who maintain mobile fuel systems will find this HEMRUNK vented cap useful. It’s ideal when you need a reliable, easy-to-service replacement that balances pressure control with leak prevention on 2" NPT transfer and diesel tank necks.