Spears Manufacturing Spears P106 Series PVC DWV Pipe Fitting, Cleanout Plug, 1-1/2" NPT Male

I didn’t expect to give much thought to a cleanout plug, but the Spears cleanout plug turned out to be one of those small parts that makes a big difference. I used it to replace a missing 1-1/2-inch DWV cleanout in a front-yard access point and later tested fitment on a spare cleanout adapter and a holding tank port. It’s a simple component that does exactly what it should—close a drain opening securely—without fuss.

What it is and where it fits

This is a 1-1/2-inch male NPT PVC cleanout plug for DWV (drain, waste, vent) systems. It threads into a female cleanout adapter or any compatible 1-1/2-inch NPT female fitting. It’s not a cap; it’s a plug—so you need a female threaded fitting already in place. I used it on a standard PVC cleanout adapter, and the taper engaged the threads predictably.

The plug is certified for DWV, with compliance markings for ASTM D2665 and D3311 and listing to NSF/ANSI 14 and UPC. That matters for inspections and peace of mind: it’s designed for the job, not a generic fitting repurposed as a plug.

Build and material quality

It’s molded PVC, which is exactly what I want in a DWV cleanout: corrosion-resistant, lightweight, and dimensionally stable enough for tapered threads. The finish on my sample was clean with crisp threads—no flashing or voids. Markings were molded-in and legible.

One note on appearance: despite some listings calling the color “copper,” mine is the expected off-white PVC. Functionally, that’s irrelevant, but worth noting if you’re trying to match a specific aesthetic in a visible location.

Threading and fit

The threads were cut clean and on-size, with the proper NPT taper. On a female 1-1/2-inch NPT DWV adapter, I was able to get it hand-tight to snug and then add a modest wrench snug to seal. The plug seated firmly without bottoming out and without cross-threading tendencies. That sounds basic, but in the land of bargain-bin plastic fittings, sloppy or inconsistent threads are a recurring pain; this one installs the way a proper NPT plug should.

For sealing, I used two wraps of PTFE tape on one install and a light bead of non-hardening thread sealant on another. Either approach worked. For DWV, you don’t need to chase a zero-bubble pressure seal, but you do want odor containment and the ability to remove the plug later. In my experience, PTFE tape helps with both and reduces the risk of a seized plug down the line.

Installation tips

• Confirm it’s truly NPT: This plug is tapered. Don’t try to force it into straight-thread fittings.
• Hand-tight plus a quarter-turn: PVC threads don’t like gorilla torque. I went hand-tight, then a gentle snug with an appropriate driver. Over-tightening can crack the female fitting.
• Use the right sealant: PTFE tape or a PVC-safe, non-hardening thread sealant. Avoid hard-setting compounds.
• Protect exposed installs: If the plug lives outdoors and is exposed to direct sun, consider a cover or keep it flush with the box. PVC will chalk under UV over very long periods.
• Keep a touch of thread lubricant if you plan frequent access: It makes future removal easier and reduces the chance of galling or thread damage.

I didn’t struggle with access or the drive feature on the plug. The profile gave me enough purchase to snug it without drama and remove it later without rounding or marring.

Performance in use

In a DWV application, “performance” means it seals odors, stays put, and is easy to remove when you need to snake a line. The Spears plug did all three. No weeping around the threads, no loosening over time, and no binding when it came time to back it out. That’s exactly what I want from a cleanout plug—predictable, boring reliability.

Temperature rating is listed at 73–140°F (23–60°C), which is standard for PVC DWV. That’s ample for residential and light commercial drains. Just don’t mistake it for a high-temperature or pressure-rated plug; it’s not intended for hot-discharge systems over 140°F or any pressurized lines.

Limitations and what it’s not for

• Not for pressure systems: This is DWV only. If you need to cap a pressurized line, look for a pressure-rated fitting.
• Not for hot industrial effluent: Stay within the 140°F limit.
• Don’t mix solvent-weld expectations: This is a threaded plug, not a solvent-weld cap. If your existing fitting is solvent-weld and unthreaded, this won’t help without installing a compatible threaded adapter first.

Sizing and compatibility notes

Most fit issues I see with cleanout plugs come from sizing confusion. Some quick pointers from my bench:

• 1-1/2-inch NPT refers to the nominal pipe size, not the literal measurement of the threads. The major OD of a 1-1/2-inch male NPT thread is roughly 1.9 inches at the first thread.
• Measure the fitting, not the old plug: If you’re replacing a missing piece, check the female fitting’s nominal size. Manufacturers often mark it on the hub.
• NPT to NPT: Make sure the female side is tapered pipe thread (NPT), not straight mechanical thread. The plug relies on the taper for sealing and holding power.
• Material mixing: Threaded PVC will mate with ABS female threads just fine on DWV as long as you seal correctly. For solvent-weld transitions, use an approved transition fitting.

If you’re unsure, take a photo of your existing fitting or bring the female fitting to the shop. It’s easier than guessing from a raw measurement of an old part.

Durability and maintenance

Outdoors, PVC will slowly degrade with UV exposure, but in a typical cleanout box or under a cover, that’s a non-issue. I’ve had no cracking or brittleness after seasonal temperature swings. If you expect frequent access, consider a light reapplication of PTFE or non-hardening sealant each time you reinstall it to keep the threads smooth and future-proof removal.

Value

It’s a small part, and you can absolutely find cheaper no-name plugs. The difference I’ve seen with the Spears plug is consistency. The threads are clean, the taper is right, and the standards markings are correct. For something that exists solely to prevent a backup from becoming a backyard odor problem, I’ll pay a few dollars more to avoid a mis-thread or a stuck plug.

If you’re managing a mix of cleanouts across a property or an RV holding tank with unused ports, having a couple of these on hand saves a drive to the store—and many stores simply don’t stock all sizes reliably. For me, the cost makes sense given the time saved and the fit reliability.

Alternatives and variants

If you’re in ABS systems and want color matching, ABS plugs exist, but make sure they carry equivalent DWV listings. Brass plugs are an option for high-abuse environments, but they add weight, can seize more easily in plastic fittings, and don’t offer the corrosion immunity of PVC. For flush or tamper-resistant installations, look for countersunk styles that accept square or slotted drivers; just confirm the drive type matches the access tools you keep on the truck.

The bottom line

The Spears cleanout plug is a well-made, standards-compliant DWV plug with clean, reliable threads and a predictable fit. Installation was straightforward, sealing was immediate with minimal torque, and removal remained easy when I needed access later. It isn’t glamorous and it isn’t trying to be—it just solves a small problem permanently.

Recommendation: I recommend it. The consistent threading, compliance markings, and no-drama installation make it a better choice than bargain generics, especially when you can’t afford a misfit on a buried cleanout or a service call. If you need a 1-1/2-inch DWV cleanout plug that won’t fight you now or later, this one is the right kind of boring.