Abstract: A buffered valve having a longitudinal passage leading to a valve chamber. The valve chamber is divided by a spacer into a front and rear chamber which are connected by a port in the spacer. A normally closed main valve member is in the front chamber which blocks the longitudinal passage. A sub-valve which has a vessel or cup-like configuration is in the rear valve chamber and is biased toward the port in the spacer by a coil spring. The sub-valve has a through hole which is blocked by a check valve. Adjustable passages are provided for connecting between the front and rear chambers of the valve. When the main valve opens, the flow of fluid from behind the main valve member to the rear chamber is restricted by the port in the spacer and the sub-valve assembly to provide a buffered valve action. When the main valve is closing, the flow of fluid is again restricted by the passage in the sub-valve and the port in the spacer to provide a buffered action.

Abstract: A main fluid passageway is provided in a main valve body between first and second ports formed and an auxiliary passageway having its opposite ends closed is also formed in the valve main body so as to intersect the main passageway. A spool is slidably mounted in the auxiliary passageway and gap spaces are provided at the opposite ends of the spool. One of the gap spaces communicates with the first port, while the other gap space communicates with the second port. A locking section is provided on the spool and a cooperating latch is provided in the valve main body. Upon occurrence of an emergency, the spool is moved to shut off the main passageway and the latch is caused to engage the locking section resulting in generation of an alarm. Under such condition, even if the pressure of the fluid at the valve varies, the locked condition of the spool can be maintained.

Abstract: An improved valve structure is disclosed, which comprises a sleeve containing a valve chamber and a valve seat therein, a valve body slidably accommodated in the sleeve and having a spherical surface, an axial port formed in the sleeve so as to communicate with the valve seat, a front chamber formed between the valve body and the valve seat, a side port formed in the side wall of the valve chamber and communicated with the front chamber, a spring receiver provided at an end of the sleeve in the opposite direction to the valve seat, a rear chamber formed between the valve body and the spring receiver, a spring disposed between the spring receiver and the valve body to bias the valve body towards the valve seat, a communication passageway formed to communicate the front chamber with the rear chamber and having a smaller cross-section area than the side port, a control passageway provided in communication with the rear chamber to communicate the rear chamber with the exterior of the valve chamber, and a control