Blind Flange With 1/2″ NPT thread in the center normally used for testing purpose.
People also call such flange as Testing Flanges
Blind flanges are generally used to blank off the ends of pipe.
NPT thread is for the Pressure gauge connection.while the most popular thread is 1/2″ NPT male for the pressure gauge.
So the blind flange should be tapped with 1/2″ NPT female thread.
NPT tapped holes and special threads available to allow pressure test connections to be fitted.
Blind Flange material available
CARBON STEEL – ASTM/ASME SA-105, A-350 LF-2, LF-6, A694, SA-516-70,
CHROME ALLOYS – A-182-F-1, F-5, F-6, F-7, F-9, F-11, F-12, F-22, F-51
STAINLESS STEEL – A-182 – F-304, 304L, 316, 316L, 309, 310, 317L, 321, 347,Alloy 20
ASTM A105 Blind Flanges with 1/2″ NPT thread is used for regular high-temperature applications
ASTM A182 F11 Blind Flanges with NPT thread can be used for oil refinery applications.
ASTM A350 LF2 Blind Flanges with 1/2″ NPT thread normally used for low temperature conditions.
Blind Flange Standard availablity:
- ANSI/ASME B16.5: 150/300/600/900/1500/2500 CLASS
- EN 1092-1:
- ASME B16.47 Series A and Series B:
- API 6A
Special design/drawing is acceptable.
for example
150 CS RF BLIND FLANGE W 3/4 NPT TAP IN CENTER
