The Blind Flange and Test Flange are the kind of wellhead flange adapter used for wellhead equipment connection. The blind and test flange are designed and manufactured according to API 6A specification and made of AISI 4130 integral forged steel.
Blind Flanges have no through-bore which are used to close off a flanged or studded end outlet. The blind flange serves a function similar to that of a plug or cap. It is used to terminate the end of a piping system. The blind flange is basically a flange that does not have a hub or a bored center.Blind flanges have the face thickness of a flange, a matching face type, and similar bolting pattern. Blind flanges can also be used to seal a nozzle opening on a pressure vessel. Because it is bolted, the blind flange provides easy access to the interior of a vessel or pipe, unlike a cap that is welded. Figure 4.24 represents the drawing symbol for the blind flange.
Test Flanges are used to close off a flanged or studded end outlet which includes a tapped test port in its center or side to allow application of pressure or the attachment of a gauge.
Specification of Blind / Test Flange
| Sizes | Working Pressure |
| 2-1/16" | 5M, 10M, & 15M |
| 3-1/16" | 5M, 10M, & 15M |
| 4-1/16" | 5M, 10M, & 15M |
| 7-1/16" | 5M, 10M, & 15M |
| 11" | 5M, 10M, & 15M |
| 13-5/8" | 2M, 3M, 5M, 10M, & 15M |
| 18-3/4" | 10M, & 15M |
| 21-1/4" | 2M, 3M, 5M & 10M |
Technical paramter of Wellhead Flange
| Pressure Ratings Flanges for Wellhead and Christmas Tree Equipment Weld Neck, Integral, Blinds, Targets and Test Blinds |
| Max Working Pressure | 2000 PSI | 3000 PSI | 5000 PSI | 10 000 PSI | 15 000PSI | 20 000PSI |
| Test Pressure | 3000 PSI | 4500 PSI | 7500 PSI | 15 000 PSI | 22 500 PSI | 30 000 PSI |
| Product Spec Levels | 1, 2, 3 and 4 | 1, 2, 3 and 4 | 1, 2, 3 and 4 | 1, 2, 3 and 4 | 1, 2, 3 and 4 | 1, 2, 3 and 4 |
| API Temp Rating | K (-60 ° C) to
Y (+345 ° C) | K (-60 ° C) to
Y (+345 ° C) | K (-60 ° C) to
Y (+345 ° C) | K (-60 ° C) to
Y (+345 ° C) | K (-60 ° C) to
Y (+345 ° C) | K (-60 ° C) to
Y (+345 ° C) |
About ZZ TOP Oil Tools
ZZ TOP Oil Tools Co., Ltd, headquartered in Xi’an City, focused on the design and production of drill stem testing tools and wellhead equipment since 2010. With the business expanding, ZZ TOP Oil Tools jointed to build the factories for wellhead equipment under the brand " JC Wellhead" and downhole tools under the brand "Techcore".
* "JC Wellhead" was estabilished in 2010 in Yancheng city, specialized in design and manufacturing of the oilfield wellhead equipment conformed with API 6A specification.
* "Techcore Oil Tools" was re-built in 2016 in Baoji city, specialized in design and manufacturing of drill stem testing tools, coiled tubing tools, wireline tools and other downhole tools.
Wellhead Product scope
Wellhead valves: Gate Valves, Plug Valves, Choke Valves, Check Valves, Mud Valves and various wellhead valve parts etc.
Wellhead Manifold: Choke and Kill Manifold, Drilling Floor Manifold, Fracturing manifold, Well Testing Manifold.
Wellhead Equipment: Wellhead Christmas Tree / X-Tree, Casing Head, Casing Hanger, Tubing Head,Tubing Hanger, Casing Spool, Tubing Spool, Drilling Spool etc.
Wellhead Adapter: Spacer Spool / Riser Spool ,Flange Adapter, Union Flange, Double Studded Adapter Flange, Welded Neck Flange, Blind Flange,Companion Flange, Instrument Flange,
Wellhead Clamp & Hub etc.
Wellhead Integral Fittings: Hammer Union, Elbow, Swivel Joint, Block Cross, Block Tee, Straight Pipe, Pipe Loops etc.
Well Pressure Control Equipment: Annular BOP, RAM BOP, Sucker Rod BOP etc
