What is an Encapsulated valve.

See  Clause  5.3. An encapsulated valve is a gas safety shut off valve which is electrically operated, but is encapsulated (fully sealed) in protective epoxy known as flame-retardant polymer.
It must have a minimum IP rating (Ingress Protection) of IP55. Connection cables are also sealed . Commonly there is also a cable gland for electrical connection. If we are using an encapsulated gas valve we need to hold documentation from the supplier.