Sthangbig Brass Fuel Vent Valve 1/2" NPTF to 5/16" Rollover Adapter — Corrosion-Resistant, Easy-Install

This compact brass adapter converts a 1/2" NPTF port to accept a 5/16" thread rollover/vent fitting, providing a corrosion-resistant, easy-to-install solution for small engines, utility vehicles, lawn equipment and portable fuel tanks. Machined from solid brass for long service life, the valve is designed to integrate into existing vent tubing and meet basic safety and containment needs in everyday use.

How does this valve stop fuel from leaking when a vehicle tips over?

The rollover valve contains an internal mechanism that seals the vent opening when the assembly is inverted, reducing the chance of liquid fuel escaping through the vent. During normal operation the vent remains open for air exchange to avoid pressure build-up.

• Internal rollover sealing element that blocks flow when inverted
• Maintains normal venting in upright orientation for pressure equalization
• Brass construction resists corrosion, so the seal stays reliable over time

What threads and fittings does this adapter fit?

This product is specifically machined for 1/2" NPTF female ports and provides a 5/16" threaded connection for rollover/vent fittings. It is not compatible with other thread standards, so confirm your tank’s thread type before ordering.

• 1/2" NPTF male thread on the adapter body
• 5/16" threaded outlet to accept standard rollover vent fittings
• Only for NPTF threads—verify thread type and pitch prior to installation

How easy is installation and maintenance?

Installation is straightforward: thread the adapter into the tank’s 1/2" NPTF port, hand-tighten and finish with a quarter-turn using a wrench for a leak-free seal. Routine maintenance is minimal—inspect the fitting and surrounding tubing for cracks or corrosion and replace if damaged.

• Hand-thread then wrench-tighten for a secure, leak-free connection
• Integrates with existing vent lines without special tools or modifications
• Periodic visual checks recommended; replace if threads or valve action degrade

Who is this for: This Sthangbig brass fuel vent valve suits DIY mechanics, small-engine technicians, landscapers, and owners of ATVs, lawn tractors, generators and portable fuel tanks who need a compact, corrosion-resistant rollover vent adapter for routine venting and spill-reduction. It’s ideal when you require an NPTF-threaded solution that’s simple to install and built to resist long-term wear.