I totally agree with that Alan if it looks like a pneumatic system is even the slightest bit unsafe it should be questioned.

Even tested its hard to say if a ram will be safe, after repeated fires of the ram it could start to fracture and become unsafe, Also I could build a ram that would take the pressure and be fine fired by a small 3/2 valve, but I could make it so that same ram would destroy itself being fed by a flow valve. Its not all about pressure with rams really, Its how you feed them. I bet theres a few rams out there that are fine being fed by a burkert, But put a flow valve in place of the burkert and it could quite possibly destroy the ram.