JYINCPED Transfer Tank Vented Fuel Cap for 2" NPT — Cast Iron 2" Base, Lockable & Spring‑Loaded Seal

JYINCPED Transfer Tank Vented Fuel Cap is a lockable, spring-loaded diesel tank cap assembly designed for 2" NPT threaded bungs that vents pressure and prevents leaks and theft.

This heavy-duty transfer tank cap replaces standard 2" threaded filler bungs and is compatible with common transfer, auxiliary, mobile and on‑vehicle fuel tanks. Built from corrosion‑resistant materials, it combines a removable vented cap and a cast iron 2‑inch base so you can safely release pressure, keep contaminants out, and secure your diesel or distillate fuel against siphoning and tampering.

How does this cap manage pressure inside a fuel transfer tank?

The cap features a two‑direction venting design and a spring‑loaded seal. When opening, the cap releases trapped vapor and pressure gradually; when closed, it allows controlled air ingress to prevent vacuum formation during fuel withdrawal.

• Two‑direction venting releases internal pressure before full removal
• Spring‑loaded mechanism maintains a tight seal while driving
• Internal gasket reduces excess vapor escape and leakage
• Prevents tank collapse by allowing air back in as fuel is drawn out

Can this cap help stop fuel theft or tampering?

Yes — the design includes a lockable tab to accept padlocks (1/4"–5/16" shackle) so you can physically secure the filler neck. The lockable feature reduces chances of siphoning and unauthorized access to expensive diesel or gasoline supplies.

• Lock hole integrated into one base tab for a compact padlock fit
• Compatible with common 1/4"–5/16" shackle padlocks (not included)
• Solid cast iron base and tab resist prying attempts
• Works on mobile, farm, and commercial transfer tanks for added security

What ensures this cap won't leak while driving or in storage?

The combination of a durable internal gasket and the spring‑loaded closure creates a reliable seal that resists vibration and road movement. Proper installation — align the notch, push down and twist clockwise — locks the cap into its seated position and minimizes leaks.

• Inside gasket forms a fuel‑tight seal when fully tightened
• Spring loading keeps constant downward pressure on the seal
• Cast iron 2" base gives a rigid mounting surface for reliable fitment
• Simple twist‑and‑push installation prevents accidental loosening

How easy is it to install and operate during refills?

Installing the cap is straightforward: it threads into a standard 2" NPT bung and uses a clear twist‑and‑notch operation for safe venting. To remove, turn counterclockwise to the notch to vent pressure, then push and twist upward to fully lift the cap.

• Fits standard 2" NPT threaded tank bungs
• Align notch, push down, and twist clockwise to tighten
• Counterclockwise to notch vents pressure before full removal
• Removable vented cap simplifies transfer and maintenance tasks

Who is this for: This JYINCPED vented diesel tank cap suits fleet owners, farmers, contractors, and anyone using transfer or auxiliary fuel tanks on vehicles and equipment. It’s made for users who need a durable, leak‑resistant replacement cap that improves safety by relieving pressure, prevents vacuum collapse, and adds a simple locking option to protect fuel assets.