The 6-Check List I Run Before Approving Any Tool or Valve Order

This list is for whoever signs off on the order before it ships — the QA reviewer, the procurement lead, the person whose name is on the receiving report when a line item gets rejected. I review roughly 200 line items a month at a valve and plumbing hardware company, and I've been doing it for four years. These six checks take about 20 minutes on a standard order and they catch the majority of what actually goes wrong.

They're not in the order most people use. The first one isn't about the product itself.

1. Start with the power source, not the tool.

When someone asks how many watts a welder uses, they usually want a single number. There isn't one. The nameplate input rating is a maximum, not an average. A 240V welder rated at 30A input is drawing roughly 7,200W at full output — but at a 30% duty cycle, the average draw over a working hour is closer to a third of that. Size the circuit off the nameplate. Size the generator off the surge.

Check: find the nameplate. Read input volts and input amps. Multiply. Then read the duty cycle line. If there's a motor in the product — compressor, recirculating pump — look for locked-rotor or start-up amps, which can run 3-5x the running draw. That's the number that trips breakers.

(Should mention: if the nameplate is illegible or missing, stop there. Don't guess off the marketing sheet.)

2. Check the rating that governs the system, not the one that's easiest to read.

On a Watts pressure relief valve — or any relief valve — most people read the inlet size first because it's the most obvious number on the tag. That's the second-most-important spec. What governs whether the valve is correct is set pressure against the system's maximum allowable working pressure, plus the capacity rating at that pressure, the temperature rating, and the medium. A valve tagged correctly for water at 150 psi is not automatically right for air at 150 psi.

Check: pull the tag and confirm set pressure against the system MAWP. Confirm you have a relief valve and not a pressure reducing valve — I've seen both ordered against the same line-item description, and the words in the catalog don't always match what's in the box. Confirm the capacity rating is at least the maximum flow the system can produce.

This is fairly basic, and it's still where I find the most errors. To be fair, part of that is that "relief valve" gets used loosely in the trade. What I mean is: the function has to match the application, not the label on the shelf.

3. Ask the supplier what they don't do.

The vendor who told me "this isn't our strength — here's who does it better" earned my business on everything else.

That sounds counterintuitive for a buyer, and I get why: one PO is easier than three. But a supplier who claims to cover valves, pumps, compressor parts, and cutting tools at the same depth is usually stocking a catalog rather than owning a category.

Where we sit: valves, recirculating pumps, hammer arrestors, and repair kits. That's the depth. If you ask about Ingersoll Rand compressor parts or a hole saw, we're not the right source, and I'd rather say so than take the order and get it half right.

Check: name three things outside the supplier's stated range and see how they answer. Granted, a generalist distributor has real value for one-stop purchasing. But for anything with a pressure rating or a warranty attached, I want a specialist who knows their limits.

4. Match compressor parts by serial range, not by photo.

For IR air compressor parts — and really for any compressor line that's been in production more than a decade — the model number on the tank sticker isn't enough. Castings get carried across model families and revisions. Two parts can look identical in a catalog photo and differ by a fraction of a millimeter in a bore, or by the material of a seal. Put the wrong one in and it may fit, run for six weeks, and fail.

Take the 919 air compressor as an example of the general problem: treat the number as a starting point, not an answer. Pull the parts breakdown for your serial range — not just the model — and confirm the part number including any revision suffix. If a listing says "fits most models" and gives no serial range, that isn't a spec. That's a guess with a photo on it.

Check: OEM part number with revision suffix, source breakdown, serial range confirmed, and — for anything with a seal or gasket — the material identified. "Rubber" is not a material spec.

5. Test accessory compatibility before you commit the crew to it.

Can you use a bi-metal hole saw on wood? Yes. Should you? Usually not.

Bi-metal saws have a fine tooth pitch and a shallow gullet, which is right for metal — it cuts thin steel cleanly and doesn't grab. In wood, that same geometry clears chips badly. The saw loads up, friction climbs, and the cut burns. Once the teeth get hot enough, you've drawn the temper out of them, and the saw is done — it won't cut metal well again either. On plywood and MDF you also get more tear-out at the exit.

For wood, you want a coarser pitch, a deeper gullet, and carbide tips if it's a repeat job. The pilot bit is the other half of this: an arbor set up for metal often runs a 1/4" pilot that wanders in softwood before it bites.

Check: tooth pitch against material, gullet depth, pilot diameter, and whether the arbor is rated for the RPM you're running. This is the step most people skip, because the dimensions match and the packaging says "heavy duty."

6. Freeze the spec in writing and inspect the first article.

In my first year, I made the classic spec error: I approved a run of roughly 1,200 finished pieces against a drawing that said "standard finish." Our standard and the vendor's standard were two different things. It cost us a rework and a three-week delay, and the rework was on our dime because our drawing was the vague one.

Now every order carries a written spec with tolerances, a material callout, and a finish callout. And we require a first-article inspection on any new part number: one unit, measured against the spec, documented, before the run starts. It's uncomfortable with a vendor you've used for years. It's also cheap.

Check: written spec with tolerances, first article approved and photographed, revision number on the drawing matching the one on the PO.

What goes wrong most often

• Sizing off the marketing number. The brochure wattage is not the nameplate wattage is not the surge wattage.
• Reading one spec. Pressure rating without capacity rating, part number without revision, tooth count without pitch.
• Trusting "universal fit." It's a claim. Per FTC guidance (ftc.gov), advertising claims have to be truthful and substantiated — that applies to your supplier's catalog and to your own cut sheets.
• Verbally approving a change. If it isn't on the drawing revision, it didn't happen.
• Skipping the first article because the vendor is "known good." That's the order where the tooling changed and nobody told you.

One caveat on all of this: the specifics above — duty cycle behavior, valve sizing logic, part-number conventions — are things I've verified within the last couple of years across our own product lines. I'm not 100% sure how some of the older compressor lines handle their revision suffixes, and I don't want to guess on a spec that matters. This was accurate as of Q1 2025. Standards, part numbering, and availability change, so verify against current documents before you sign anything.