Flame King ACR-2a two-stage auto changeover propane regulator for RVs (Without Pigtails) — 11 in WC, 345,200 BTU

Flame King ACR-2a is a two-stage automatic changeover propane regulator that lets dual-tank RV systems switch from an empty cylinder to a reserve without interrupting gas flow. The Flame King ACR-2a fits RVs, vans, and trailers equipped with dual propane cylinders and provides a steady, factory-set delivery pressure so appliances keep running while you replace an empty tank. Designed for continuous service, the regulator is UL listed, rated for up to 345,200 BTU and optimized for use with inverted-flare pigtails and Flame King hoses. It uses a double-stage design to hold consistent gas pressure and built-in lockout settings to prevent improper changeover.

How does the ACR-2a keep my propane supply continuous?

The ACR-2a automatically senses when the primary cylinder is depleted and switches flow to the reserve cylinder without shutting down appliances. This eliminates downtime while removing and refilling the empty tank.

• Automatic changeover when primary tank pressure drops
• Two-stage regulation for smoother pressure control
• Lockout threshold up to 14.9" WC to prevent cross-feeding

What connections, pressure settings, and performance should I expect?

Inlets use 1/4" SAE inverted flare fittings while the outlet is 3/8" NPT female pipe thread for common RV plumbing. The regulator is factory set at 11" water column (WC) delivery pressure and can support appliances up to the unit's 345,200 BTU rating.

• Inlets: 1/4" SAE inverted flare; outlet: 3/8" NPT female
• Factory set delivery: 11" WC; lockout up to 14.9" WC
• Rated capacity: 345,200 BTU for high-demand systems

Which hoses and pigtails work with this regulator?

The regulator pairs with Flame King inverted-flare pigtails and the 48-inch Thermo Plastic hose for reliable connections. NPT-style pigtails are not recommended; the unit is assembled with thread-locker at pigtail adapters to maintain leak-free fittings.

• Compatible pigtails: E12INPT, E15INPT, E18INPT (inverted flare)
• Compatible hose: Flame King 48-inch Thermo Plastic (100383-48)
• Thread-locker applied at adapter connections to prevent loosening

How does the regulator improve safety and maintenance?

The ACR-2a is UL listed and built with safety-minded assembly practices including Loctite on critical fittings, reducing the risk of threads loosening during vibration or travel. Regular inspection of fittings and hoses is still recommended to ensure leak-free operation.

• UL listed construction for recognized safety standards
• High-strength thread-locker on pigtail adapters to secure connections
• Easier cylinder swap without shutting off appliances reduces user error

This regulator is for RV, van, and trailer owners who run multiple propane appliances and want uninterrupted service while swapping tanks. It suits installers and DIYers comfortable with inverted-flare connections and those who prefer a two-stage regulator for steadier appliance performance. Note that compatible inverted-flare pigtails and hoses are recommended, and NPT pigtails should be avoided to maintain the intended fit and function.

FAQ

Q: Can I use NPT pigtails with the ACR-2a?

A: No. NPT pigtails are not recommended; use inverted-flare pigtails for proper fit and safety.

Q: What pressure does the regulator deliver?

A: The regulator is factory set to 11" WC delivery pressure, with a lockout up to 14.9" WC.