Rupture discs
are pressure differential devices; therefore it is essential
to prevent pressure build-up in the interspace between
relief devices. The space between the rupture disc and
the safety valve shall be provided with a means for
preventing unacceptable build up in pressure, as specified
in EN ISO 4126-6:2003 section 5.4.2.c. Elfab’s
Excess Flow Valve provides this essential facility.
The Excess Flow Valve remains open under very low flow
rates, possibly caused by temperature changes of interspace
gas, and closes when exposed to high flow rate, as occurs
when a rupture disc functions. |
