Champion Big-Lock Plug Cap - Plain and 1/2 in FNPT Ported (73mm to 220mm)

A Champion Big-Lock plug cap closes off the end of a grooved aluminum main. It comes in two forms: plain, which simply terminates the run, and ported, with a 1/2 in female NPT tapping in the face.

The ported version is the more useful of the two more often than people expect. That 1/2 in port is where a pressure gauge goes at the far end of a main, or a drain at the bottom of a riser, or a future take-off that costs nothing to leave in place today.

Choose your size and port from the dropdowns above.

Model Selection Chart

A plug cap seats on a grooved pipe end, so it needs a straight union coupling to hold it on. Order one per cap.

Spend the Extra and Take the Port

The ported cap costs between $19 and $67 more than the plain one at list depending on size. For that you get a permanent 1/2 in NPT tapping at the end of the run, which is worth having for three reasons.

• A gauge at the far end of the main. The pressure at the compressor tells you almost nothing. The gap between the compressor gauge and a gauge at the end of the header is your real distribution loss, and it is invisible without this.
• A drain at a low point. If the capped end is the bottom of a riser or the low point of a pitched main, that is exactly where condensate collects, and the port takes a drain valve directly.
• A future take-off. Plug it today, use it in three years when something gets added at that end of the building.

Plan the Main to Grow

Nobody has ever regretted leaving a capped stub in a compressed air main. What plants regret is an undersized header with nowhere to tie in, because adding a branch later means isolating, draining, cutting and re-grooving a live main.

When we lay out a Big-Lock system we normally put a capped tee wherever the floor plan looks likely to change: the end of a bay, the edge of an area earmarked for a cell, the point where a second compressor or receiver might land. A plug cap is $65 to $207. A shutdown to cut into a 6 in header is not.

Shared Technical Specifications

Specification note. Champion's price list publishes description, part number and list price for the Big-Lock range and nothing else: no pressure rating, no temperature band, no weights and no dimensions, and we have not found a Big-Lock datasheet that supplies them. This listing states only what Champion publishes. Ask us and we will source anything further from the factory before you order.

Ideal Applications

Terminating a plant main at the far wall, capping the spare leg of a junction tee left in for future expansion, closing a stub during a phased install so the rest of the plant can run, blanking a branch taken out of service, and, in the ported version, fitting a gauge or a drain exactly where the system needs one.

Building a Complete Big-Lock System

• Big-Lock aluminum pipe, 73mm to 273mm
• Straight union couplings, one per plug cap
• Junction tees and reduction tees, the usual thing a capped stub hangs off
• 90 and 45 degree elbows and street elbows
• Threaded adapters and reducers
• Quick-Lock 2.5 in liquid filled gauges, which fit the 1/2 in port on the ported caps

Ordering Notes

• All Big-Lock products and accessories are NO CANCEL / NO RETURN, per Champion's current price list.
• Freight: freight collect from Huntersville, NC 28078 or Las Vegas, NV 89113.
• Shipping weights: Champion publishes no weight for any Big-Lock fitting, so no catalog weight is carried on these variants.
• Photography: Champion publishes no photograph of the Big-Lock plug caps, so this listing is deliberately shown without an image rather than with a stand-in from another manufacturer's grooved range.