Hello Surfer.
The first document Beagler points show is from AUTOGAS, and represents that company's policies, Other supplier will have their own policies concerning the practice.
Provided a company's policies stay within the bounds set by statutory regulations they have the absolute right to decide what products they allow to be used on their premises. The company is responsible for Health and Safety on the site, and they are required to take whatever measures they consider necessary to to protect health and safety.
In their advice the key points to look at are:-
AUTOGAS said:
FILLING OF USER OWNED, PORTABLE REFILLABLE LPG
CYLINDERS AT AUTOGAS REFUELLING SITES
It is our advice that user owned, portable LPG cylinders should not be
refilled at autogas refuelling sites.
If you own your own portable refillable vessel, then this bar applies regardless of what safety features it may have built into the vessel. Its worth considering the fact that the majority of personnel who operate filling sites will not be fully versed in the the capabilities of every user owned refillable vessel, and thus they should err on the side of safety which means not allowing any portable bottle to be filled on site.
AUTOGAS said:
Vessels which are attached to a vehicle for heating or cooking (on camper
vans or similar) present similar risks on filling to those for propulsion
purposes and may be permitted to be re-filled at autogas refuelling sites
provided they:
• remain in-situ for refilling; and
• are fitted with a device to physically prevent filling beyond 80%; and
• are connected to a fixed filling connector which is not part of the
vessel...................
The final point also prevent solo vessels from being refilled.
The HSE web page only directs the relevant official bodies that oversee the licensing of sites to liaise, and to observe the LPGA's codes of practice. It does not empower the consumer to try and force an automotive gas provider to make their facilities available to owner used portable vessels. That decision is strictly still within the realms of company policy.