瓶帽 meaning in English

bottle capsule
capsule

Check that cap or guard is firmly fixed before handling the cylinder
操作气瓶时检查瓶帽、或防护罩是否牢固。
When not connected to the filling rack , cylinders must be capped and secured against falling
气瓶未连接到充气排前，必须戴瓶帽、且要固定以防倒瓶。
Never lift a cylinder by the cap , valve or guard , unless it has been specifically designed for the purpose
不要用瓶帽、阀、护罩提升气瓶。除非专门设计举重用的。
When rolling cylinders do not use the valve handwheel as this could open the valve . only handle capped cylinders
滚瓶时不要抓住瓶阀，否则会打开阀门，操作时要戴瓶帽。