Pressure reducing valve for gas

A pressure reducing valve for gas in which a valve mechanism (20) having opening in a central part thereof a valve hole (68) that communicates with a low pressure passage (85, 86, 94, 119) and a low pressure chamber (83, 84, 116) and comprising a valve body (59) that is capable of being seated on a valve seat (58) facing a valve chamber (66) communicating with a high pressure passage (27, 28, 30, 64) is housed within a body (16, 16′) such that the valve body (59) is connected to a pressure receiving member (115) operating in response to pressure of the low pressure passage (85, 86, 94, 119) and the low pressure chamber (83, 84, 116), characterized in that the body (16, 16′) is formed by joining two, that is, first and second body members (18, 19;

• 18′, 19′) having different strengths, the body (16, 16′) being formed by joining the second body member (19, 19′), which has a low strength, and the first body member (18, 18′), which has a high strength and has an insertion hole (25) coaxially housing the valve mechanism (20), so that the second body member (19, 19′) and the first body member (18, 18′) overlap each other in a direction along an axis of the valve body (59) while forming therebetween a pressure reduction chamber (83), which is the low pressure chamber, and a circular cross-section fitting projection (18a) projectingly provided integrally with the first body member (18, 18′) so as to be coaxial with the insertion hole (25) is hermetically fitted into the second body member (19, 19′).

A pressure reducing valve for gas in which a valve mechanism (20) having opening in a central part thereof a valve hole (68) that communicates with a low pressure passage (85, 86, 94, 119) and a low pressure chamber (83, 84, 116) and comprising a valve body (59) that is capable of being seated on a valve seat (58) facing a valve chamber (66) communicating with a high pressure passage (27, 28, 30, 64) is housed within a body (16, 16′) such that the valve body (59) is connected to a diaphragm (115) operating in response to pressure of the low pressure passage (85, 86, 94, 119) and the low pressure chamber (83, 84, 116), [1] characterized in that the body (16, 16′) is formed by joining two, that is, first and second body members (18, 19;

• 18′, 19′), a groove (110, 133, 134) is provided in at least one of joining faces of the body members (18, 19;
• 18′, 19′), the groove (110, 133, 134) forming between the body members (18, 19;
• 18′, 19′) in a state of being joined together a housing chamber (132) for housing heating means (131) or a heating medium passage (109) through which a heating medium flows, the first body member (18, 18′) has an insertion hole (25) coaxially housing the valve mechanism (20), a circular cross-section fitting projection (18a) projectingly provided integrally with the first body member (18, 18′) so as to be coaxial with the insertion hole (25) is hermetically fitted into a fitting hole (80) of the second body member (19, 19′), the second body member (19, 19′) clamps a peripheral edge part of the diaphragm (115) between the second body member (19, 19′) and a diaphragm cover (17) so that the diaphragm (115) is positioned coaxially with the fitting hole (80), and the valve body (59) is connected to a central part of the diaphragm (115).