AS EN 50089:2013 Cast resin partitions for metal-enclosed gas-filled high-voltage switchgear and controlgear
Design pressure
Since in service most partitions have the same or smal1 differential pres – sure on either side, the significant pressure is that termed the mainte- nance pressure, this will exist when the partition is pressurized on one side and ma intenance is being carried out on the other side at a tmospher ic pressure.
There are designs however, where the partition is pressurized on one side and atmospheric pressure exists at a11 times on the other side.
In both cases the pressure to be considered on the pressurized side of the partition is the pressure at maximum ambient temperature with solar radia- tion effects (where applicable) and rated continuous current (where appli- cable) .
In both cases the pressure so derived is the design pressure.
The manufacturer may if he so wishes prescribe that the pressure on the pressurized side of the partition be lowered to a specified and controlled pressure during maintenance， in such cases this pressure is the design pressure.
4 Materials
Any suitable cast resin system, liquid or solid and any suitable filler,e. g. alumina or bauxite, may be used provided the requirements of this standard are met .
The partitions shall be traceable to a given batch of material and manu- facturing process either by serial number, batch number or date. (Refer to clause 8) .
5.1 Purpose
Consideration for design of partitions for gas insulated switchgear pre- scribed in this section takes into account that the partitions are subjec- ted to particular operating conditions (clause 1) which distinguish them . from parts for compressed air receivers and similar storage vessels.
5.3 Stresses due to pressure
The dimension of a partition under pressure may be determincd by any method using the design pressure as defined in subclause 3.1 provided the requi rements of clause 7 are met.
HOTE: Pressure stresses due to an internal fault are not considered in the design of partition since after such an occurrence the partition would be carefully checked and, if necessary, replaced.