How to Identify an Industrial Valve From Its Nameplate

Start with the complete assembly

Before zooming in on a tag, photograph the complete valve from several angles. The overall body shape, end connections, stem arrangement, bonnet, operator, actuator, tubing, and accessories provide context that a cropped nameplate cannot. A buyer may recognize a control-valve series or pipeline design from the assembly even when a worn tag is difficult to read.

Take one photo from each side and one from above. Include a ruler, tape measure, pallet, or another safe scale reference when the nominal size is uncertain. Do not remove an actuator, positioner, pilot, solenoid, or gear operator before the first review because the original combination may be more useful than separated components.

Capture every tag and casting mark

Industrial valves may carry information on a riveted metal nameplate, an actuator label, a positioner label, a bonnet tag, a casting mark, or stamped flange edges. Photograph each one straight-on in diffuse light. Wipe loose dust with a dry cloth if safe, but do not grind, wire-brush, repaint, or stamp the surface.

Use the phone's standard camera rather than a social-app camera because the original file usually retains more detail. Tap the tag to focus, hold the phone parallel to the plate, and take a second image with flash off if glare obscures the characters.

• Manufacturer and complete model number
• Serial, shop, figure, or tag number
• Nominal pipe size and pressure class
• Body, bonnet, trim, seat, or liner material
• Set pressure, flow direction, voltage, or actuator action
• Applicable standards or certification marks

Distinguish size from pressure class

A marking such as 6 300 may indicate a six-inch valve in ASME Class 300, not a quantity or model. Size is commonly expressed in inches or DN, while pressure class may appear as 150, 300, 600, 900, 1500, or 2500. Other systems use PN ratings. The same nominal size can have very different market value depending on class, material, and design.

Photograph both flange faces or end preparations. A butt-weld valve, socket-weld valve, threaded valve, and flanged valve of the same size are not interchangeable. Flange drilling and facing also matter, so protect sealing surfaces and include a clear end view.

Record the material accurately

Body markings such as WCB, LCB, CF8M, WC9, C5, or A105 can indicate casting or forging grades. They should be transcribed exactly rather than interpreted from color. Paint is not reliable proof of alloy, pressure rating, or service. When material certificates, purchase orders, or manufacturer data sheets are available, include them with the submission.

Internal trim and soft goods are often more difficult to confirm from the exterior. Do not guess. State that the trim is unknown unless a nameplate, bill of material, or service record identifies it. Clear uncertainty is more useful than a confident but incorrect description.

Include the actuator and controls

Actuated valves may have several separate identification points. Photograph the actuator model and output, spring range or supply pressure, fail action, positioner model, solenoid voltage, limit switch box, and mounting arrangement. Electric actuators also require voltage, phase, frequency, torque or thrust, speed, and enclosure information.

Keep brackets, couplings, handwheels, declutch mechanisms, tubing, and control accessories with the assembly. A complete package gives a buyer more options and reduces uncertainty about compatibility.

Build a useful inventory sheet

For more than a few valves, use one spreadsheet row per unit or matching group. Assign a simple item number and place that number on a removable tag visible in the photos. The sheet should include quantity, manufacturer, model, size, class, material, valve type, actuation, condition, location, and notes.

Name image files with the same item number. This small step prevents a common problem: an excellent group of photos that cannot be matched to the list. A buyer can work faster when every claim traces to a visible tag or document.

• Item number
• Quantity
• Valve type
• Manufacturer and model
• Size and class
• Material
• Actuator or operator
• New, unused, or used condition
• Pickup city and ZIP code

Send what you know—without guessing

A complete tag is ideal, but incomplete information should not stop a first submission. Send the full-valve views, every readable marking, quantities, and a short explanation of where the equipment came from. An experienced buyer can often identify the next detail needed.

The goal is not to create a formal engineering record. It is to establish enough identity and condition information to determine whether the inventory is a purchasing fit and what additional verification is appropriate.