valve бөмбөлгөн тээрэм suppliersvalve grindin нийлүүлэх
•Valves did not meet the Back Flow Integrity Test.•Valves had to be slammed closed to seal off. failed. Valves had to be slammed closed to seal off-Some valves failed even though •Squeezed soft seal•The check had to be pushed off the seat by raising theThe check had to be pushed off the seat by raising the. annulus pressure to more than ...