How to Replace a Rubber Diaphragm in Flange Standpipe Gauge

Posted on Sep 01, 2017 by Kathy DeGlandon

Crown gauges are built to last. So, when it's time for routine maintenance or when a rubber cup blows, knowing how to replace on is very important for proper pressure management.

How to Replace Rubber Cup Diaphragm

Crown flange standpipe unitized pressure gauges are durable and will withstand the harshest drilling rig conditions. With regular, routine maintenance, Crown gauges will last for years and provide accurate, dependable pressure readings. Each Crown flange gauge comes complete and ready to be set up and used. Each gauge has a rubber cup diaphragm already installed, and this rubber cup diaphragm protects gauge internals from harsh drilling fluids. Regular maintenance is needed to ensure that Crown gauges will perform at peak performance, and part of this maintenance is inspecting the rubber cup diaphragm. When it is time to replace the rubber cup diaphragm, use the items in our CKT-UMG Repair Kit, and follow the steps in this video, and your gauge will be back on the line in no time. 






How to Replace a Rubber Cup Diaphragm Video Transcript:

Step One:  Flip UMG on side with gauge face down to expose the bottom of the flange. Placing the gauge face down will ensure that the glass will be protected during diaphragm removal.

Step Two: Using a 1/2" ratchet with no socket, place ratchet into center hole in bottom of flange.

Step Three:  Use ratchet to loosen flange retainer nut which holds rubber diaphragm in place.

Step Four: Once ratchet has loosened retainer nut, finish loosening nut by hand and then remove it. Caution: Threads of retainer nut may be sharp.

Step Five: Use needle nose pliers to grab the lower rim of diaphragm. Pull on diaphragm to remove. If diaphragm has ruptured, be sure to remove all pieces.

Step Six: Lay flange gauge back on side to expose center hole. Place new diaphragm on finger and push into the hole until snug. Diaphragm will rest in grove located near opening. 

Step Seven: Replace retainer nut and finger tighten in place.

Step Eight: Use ratchet to tighten retainer nut in place. Do not over tighten.


Rubber cup diaphragms CD288 for flange unitized pressure gauges are available by calling a Crown representative at 1-877-908-3790 or by emailing Have questions? Give our friendly, knowledgeable staff a call. We are more than happy to assist you.

With proper service and repair, your  Crown UMG will provide years of service. Proper service and repair, such as replacing worn diaphragm cups, is important to the safe and reliable operation of all Crown equipment. The service procedures recommended by Crown and described above are recommended methods of performing service operations. Some of these service operations require the use of tools specifically designed for their purposes. These special tools should be used when and as recommended. For more information or for any questions, contact our friendly, knowledgeable staff at or at 1-877-908-3790. 

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