1. Start with your service conditions

Write down these details before comparing options:

• Medium: what fluid or gas the line carries, and whether it is corrosive.
• Design pressure and temperature: the class or PN rating your piping system needs.
• Mating flange: its size, pressure rating, standard and facing type.
• Purpose of the closure: permanent end closure, temporary isolation, future expansion, inspection access or pressure testing.

Check the service conditions carefully. The source description contradicts itself. One part says the flanges "are for use with low-pressure applications in noncorrosive environments." Other parts describe use in "high-pressure and high-temperature environments." Do not assume either statement fits your project. Ask for written confirmation of the pressure-temperature rating for the material, class and size you plan to order.

2. Match pressure class and size

The published ranges are:

The blind flange has to match the size and rating of the flange it bolts onto. A product line that covers a wide range does not mean every combination of size, class and material is available. Confirm your exact combination when you request a quote. The "S.A 12in – 60in" entry is not explained in the source, so ask what it refers to.

3. Choose the material

Listed materials:

• Carbon steel (CS): ASTM A105, P235GH, P245GH, P250GH, P265GH, ST37-2
• Stainless steel (SS): listed as ASTM A182 / 304 / 306

The descriptive text also mentions alloy steel, but the specification table names no alloy steel grade. If you need alloy steel, ask for the exact grade. Choose the material based on the medium, temperature and corrosion conditions, and confirm the stainless steel grade designation as written in the listing before you order.

4. Confirm the standard

Listed standards: ASME, EN, JIS, DIN, BS, KS, GOST, SABS and ATK. Name the exact standard and edition your project uses. Bolt pattern, dimensions and rating have to match the mating flange.

5. Check the facing and the gasket

The product description refers to bolting two flat-surface flanges or two raised-surface flanges of the same size together with a gasket. The gasket is sold separately. When you compare blind flange types for your line, match the facing of the mating flange. Then choose a gasket that suits the fluid and pressure. The source also notes that flange faces and gaskets should be clean and free of debris before installation.

6. Select a surface coating

Listed coatings: black paint, galvanize, grease and epoxy paint. Choose one based on storage, transport and site conditions, and state it on your purchase order.

Industries named in the source

The product description names oil and gas, chemical processing, petrochemicals, power generation, water treatment and shipbuilding. Being used in an industry does not show that a product suits a specific service. Base your decision on the checks above.

When this recommendation does not apply

• Your required size, class, material or standard is outside the listed ranges.
• You need an alloy steel grade, a facing type or a certification that the source does not document.
• You need confirmed performance in corrosive, high-pressure or high-temperature service and have no written supplier confirmation.
• You need pricing, lead time or delivery commitments. These are not covered by the available material.

Pre-order checklist for a blind flange

1. Size (DN or inch) and pressure class or PN
2. Standard and edition
3. Material grade
4. Facing type that matches the mating flange
5. Surface coating
6. Gasket sourced separately
7. Written confirmation of service limits for your medium, pressure and temperature

If you are evaluating a blind flange for sale for an upcoming project, send this checklist to HEBEI JIUYUAN PIPELINE MANUFACTURING CO.,LTD . with your inquiry so the quote matches your requirements.