The two halves of the vessel and the diaphragm are retained by a crimped collar to give a pressure tight seal on sizes 8 to 25 litre and on larger sizes by a welded joint.

• Non-replaceable diaphragm.
• Epoxy coated in grey.
• Suitable for flow temperatures up to 120°C, resistant to ethylene or
• propylene glycol mixtures and has low gas permeability.
• Altecnic expansion vessels are all tested according to the Pressure Systems Directive.