FEP Bladder System for Hydrogen Peroxide Tanks

22/07/2016

Working with MT Aerospace, Holscot developed an FEP bladder system based on FEP film to contain drinking water for the International Space Station. The FEP bladder comprised a liner which was bonded to the metallic tank and a collapsible FEP Diaphragm which assisted in the total expulsion of the potable water. The two components were welded together to ensure complete integrity, using techniques developed and refined by Holscot. More details can be seen on our case history page.

FEP Bladder Welded location of breather tube

Welded location of breather tube

Following on from this and taking advantage of FEP’s blanket chemical resistance, Holscot developed a bladder system for the containment of Hydrogen Peroxide. The use of Hydrogen Peroxide as a Space Propellant presents unique difficulties – in particular the decomposition of the liquid and the resultant build-up of oxygen. Thus, a way had to be found to remove the accumulation of the oxygen.

FEP Bladder - Welded Support Cleat

Welded Support Cleat

FEP Bladder System for Hydrogen Peroxide TanksIn order to do this, Holscot incorporated a breather tube which was located at the summit of the bladder, coiled around the tank and supported by preformed and welded FEP cleats. The breather tube was subsequently passed through a boss to provide an exit path.

There were concerns that the welded supports and the weld at the summit of the dome would affect the collapsing of the diaphragm and that weak points would be generated at the weld areas which would ultimately lead to failure at those points. However the diaphragm incorporating the welds was test cycled and failure only occurred after 36 cycles and that was at a location away from the welded areas.

Are you investigating the use of FEP for containment of Hydrogen Peroxide? We will be happy to discuss your project to offer solutions. Please either complete the contact form here or email us at sales@holscot.com

FEP Bladder System Test Cycle

FEP Bladder System Test Cycle