Reading a valve compound datasheet: which fields matter for selection

1. What a datasheet can and cannot prove

A valve compound datasheet is a laboratory summary. It describes one material, as tested by its maker, under the maker's chosen conditions. It is screening evidence for a shortlist, never proof of performance in your valve.

The confirming evidence comes later, in the field. For a valve passing at the seat, that means a seat-leak test under agreed conditions. Examples include pressure decay across the closed valve, or double block and bleed monitoring.

Hold this split in mind while you read. The fields help you reject poor matches early and compare strong ones fairly. They cannot tell you how a compound behaves in a worn seat, in your medium, at your temperature.

2. The fields that matter most

Check these fields first, and treat any of them missing as a reason to ask questions. They carry most of the selection risk.

1. Purpose and type. Cleaner, lubricant or sealant, and whether a sealant is non-hardening or of a setting type. The choice has consequences for later maintenance, as valve lubricant versus valve sealant explains.
2. Service medium compatibility. The sheet must name the media the compound suits, including dry gas where relevant. Organic sealants can harden in dry gas and seize valves; this is known industry behaviour, so ask directly about dry gas duties.
3. Temperature range. Look for an application range and a service range. A compound that injects easily may still be wrong for the line temperature.
4. Pressure capability. This states the differential the compound film can help seal against, under stated test conditions.
5. Material compatibility. Effects on elastomers, coatings and valve internals should be stated, not assumed.
6. Application method. Suitability for injection through fittings, with any limits on equipment or fittings.

3. Warning signs on a weak datasheet

Some sheets are written to sell rather than to describe. Warning signs are usually easy to spot once you look for them.

1. Claims without conditions. A sealing claim with no stated pressure, medium or temperature is a claim about nothing in particular.
2. Missing ranges. Without a service temperature range or a medium list, you are guessing rather than selecting.
3. Unnamed test methods. A figure carries weight only when the method behind it is named and repeatable.
4. No storage life. Stored compound changes behaviour over time, and the sheet should state the limit.

Where a field is missing, ask rather than infer. The list of ten questions to ask any valve sealant supplier covers these gaps. A serious supplier answers plainly, in writing.

4. Comparing two datasheets fairly

Datasheets from different makers rarely share a format. The same field name can rest on different test methods, so figures may not compare directly. Read the conditions behind each number before you rank one compound above another.

Trade-offs are normal, and a good datasheet makes them visible. A compound suited to dry gas may be a poor choice in another service. A firm film that seals well can raise operating torque, which matters for actuated valves, as compounds for actuated valves discusses.

Match the whole sheet to your seat design and injection system. The guide to sealant selection by seat design and service medium works through that matching. When you shortlist compounds, record which fields decided the choice. That record makes later reviews faster and more honest.

5. From datasheet to field evidence

Before any compound goes into a valve in service, three gates apply. The valve must have injection fittings in good condition. The valve design and the service must suit injection, and site rules with the permit-to-work must allow the job. Where OEM documentation exists, consult it for limits and warranty terms.

After treatment, the confirming test is a seat-leak test under agreed conditions, for example double block and bleed monitoring or a witnessed leak test. API 598 and ISO 5208 are factory acceptance references, not field results. If the valve still passes after sound treatment, the honest endpoint is a proper assessment of the seat, not another datasheet.

For the wider decision, the valve sealant buying guide places datasheet review inside the full purchase process. You can also review our valve sealants against the fields above, then request the product guide through an enquiry.