How to Read a Valve Data Sheet - Valve Knowledge Hub

The Short Answer

A valve data sheet is a structured table that captures everything a supplier needs to quote and build the correct valve: service conditions (media, flow, pressures, temperature), valve requirements (type, size, class, ends, operator), materials (body, bonnet, trim, seats), testing and documentation (test standard, leakage class, certificates), and accessories. Read it in that order: if the service conditions are complete and the requirements unambiguous, the supplier can quote correctly; if they are vague, you will get a valve that only looks right.

The Sections, Explained

1. Header and Reference

Valve tag number, line number, project, standard references, and revision. Always check the revision — an outdated data sheet can quote the wrong standard edition or the wrong materials.

2. Service Conditions (the Foundation)

Fluid and phase: what flows, with composition and impurities.
Flow rates: normal, maximum, minimum (units matter — mass or volumetric).
Pressures: upstream and downstream at each flow, plus the maximum shutoff differential pressure (the worst case for actuator and seat sizing).
Temperature: operating and design; check the extremes, not just the normal.
Specific gravity / density, viscosity: needed for Cv and cavitation calculations.
Special conditions: corrosive, sour (H2S), erosive, flashing, cavitation, noise limits, thermal cycling.

Common error: leaving the shutoff ΔP blank — then the actuator and seat get sized for operating ΔP and fail at shutdown.

3. Valve Requirements

Type: gate, globe, ball, butterfly, check — plus any subtype.
Size (NPS/DN) and pressure class (150/300/600/900/1500/2500).
End connections: flanged (to ASME B16.5 / B16.47), butt-weld, socket-weld, threaded.
Face-to-face / end-to-end dimension and the standard (ASME B16.10 for flanged and weld-end steel valves; API 6D for pipeline valves).
Operator: handwheel, gearbox, pneumatic/electric actuator, or bare stem; fail-safe position if actuated.
Mounting: ISO 5211 pad dimensions for actuators.

4. Materials

Body and bonnet: cast designations (WCB, CF8M, etc.) with the material standard.
Trim: seat, disc/wedge/ball, stem — the corrosion and wear-critical parts. Standard trim (13Cr) vs. stainless vs. hard-faced must be explicit.
Seats: soft (PTFE/PEEK) or metal, and any fire-safe requirement.
Gaskets and packing: material per service temperature and fugitive-emission requirements.
Bolting: material and NACE compliance if sour.

5. Ratings and Design

Pressure-temperature rating per ASME B16.34 (or the applicable standard) — the data sheet usually states the class and design conditions; verify the rating table covers them.
Standards: API 600/603/6D, ASME B16.34, and the test standard.

6. Testing and Inspection

Test standard: API 598 (or ISO 5208 / EN 12266).
Shell test pressure and seat test requirements; seat leakage class (Rate A/B/C, or Class VI bubble-tight).
Optional tests: fire test (API 607), fugitive-emission test (ISO 15848), gas test, high-pressure gas test, NACE compliance.
Witnessing: whether inspection is witnessed by the purchaser or a third party.

7. Documentation and Certification

Material certificates (EN 10204 3.1/3.2) for pressure parts and trim.
Test certificates and the data book contents.
Nameplate requirements, traceability, and special inspection (NDE: radiography, dye penetrant, ultrasonic) — specify when required.

A Quick Read-Through Checklist

When reviewing a valve data sheet before sending to a supplier (or checking a quote against it):

[ ] Tag, line, standard, and revision are current
[ ] Media and phase are explicit (including impurities)
[ ] Normal, max, min flows given with units
[ ] Operating AND shutoff ΔP given
[ ] Design temperature covers the worst case
[ ] Valve type, size, class, ends are unambiguous
[ ] Trim material specified (not just “standard”)
[ ] Seat type and any fire-safe requirement stated
[ ] Test standard and leakage class stated
[ ] Documentation requirements (material certs, reports) listed
[ ] NACE / fugitive-emission / special conditions flagged

How to Fill One Out Properly (for the Engineer)

Never leave the shutoff ΔP blank. It drives actuator and seat selection.
Be specific about media. “Hydrocarbon” is not enough — give composition, H2S, chlorides, solids, water cut.
Give the worst-case temperature, not the normal. Seats, packing, and ratings all depend on the maximum.
State the trim explicitly. If you want 316 trim, write it; “standard trim” on a carbon steel valve is 13Cr.
State testing and leakage requirements. If bubble-tight is needed, write “seat test per API 598, zero leakage (Rate A / Class VI).”
Specify documentation up front. Material certificates and test reports are easier to demand at the inquiry stage than after delivery.

Data Sheet vs. Datasheet Forms

Most projects use a standard form (e.g., a project-specific datasheet or a manufacturer’s blank). The content matters more than the form — but a good form enforces completeness. If your project has a template, use it and fill every field that applies; leave nothing to “standard practice” unless the standard is named.

Common Mistakes When Reading a Supplier’s Quotation Against the Data Sheet

Accepting “or equivalent” substitutions without verifying the trim, seat, and test requirements match.
Ignoring the face-to-face dimension. A valve with the wrong face-to-face won’t fit the piping; check it against ASME B16.10 or API 6D.
Not checking the test standard edition. Testing criteria differ between editions; confirm the referenced edition is acceptable.
Assuming “NACE compliant” without the environment. Compliance depends on H2S partial pressure and pH; the data sheet must state the conditions.

Conclusion

The valve data sheet is the engineering contract: complete service conditions in, correct valve out. Read it top to bottom — service, requirements, materials, testing, documentation — and verify every line against the quote. The few minutes spent filling it in completely prevent the expensive mismatch that shows up at the plant: the wrong trim, the weak actuator, or the missing NACE cert.