截止阀数量名称止回阀的工作原理有哪些呢截止阀数量名称保温截止阀：BJ41W、BJ41Y、BJ45H、BJ45Y、BJ45W　　锻钢截止阀：J61Y、J61H、J41H、J11H　　波纹管截止阀：WJ41H、WJ41Y、WJ41W　　仪表针形截止阀：J13、J23　　低温截止阀：DJ41Y、DJ41W...