Backflow preventing valve construction

Claim 2

In a backflow preventing valve including a body having an inlet passage for connection to a source of fluid; an intermediate chamber fluidly connected to the inlet passage via an inlet check valve; an outlet passage fluidly connected to the intermediate chamber via an outlet check valve, and for connection to a receiver of fluid; an exhaust passage fluidly connected to the intermediate chamber via a relief valve and opening to atmosphere; a diaphragm chamber fluidly connected to the inlet passage and to the operating chamber; and a diaphragm in the diaphragm chamber to divide the diaphragm chamber into an inlet pressure portion and an intermediate pressure portion, said inlet pressure portion being in fluid communication with the inlet passage and said intermediate pressure portion being in fluid communication with the intermediate chamber, the improvement comprising the provision of: a resilient connecting means between the diaphragm and the relief valve for operably connecting the relief valve to the diaphragm while allowing slight relative movement therebetween, whereby upon variations in the fluid pressure in the valve housing, the diaphragm can flex slightly without moving the relief valve, but upon a leak of fluid from said outlet passage into said intermediate chamber, said diaphragm will flex beyond the limited amount allowed to move the resilient connecting means and cause the relief valve to open and exhaust the excess fluid to avoid possibly contaminating the fluid supply.

Claim 3

The invention as defined in claim 1 wherein the resilient connecting means includes a spring with one end attached to the relief valve and the other attached to the diaphragm.

Claim 4

The invention as in claim 1 wherein at least one of the check valves comprises: a valve seat member on the body and having a piston receiving opening therein, a valve piston member mounted on the body for movement relative to the seat member between open and closed positions, means for biasing the piston member to the closed position in the opening on the seat member, one of said members having a frustoconical sealing surface adjacent the other member, the other of said members having a sealing ring receiving grove opening generally toward the sealing surface, and a sealing ring in said groove for wedging sealing engagement with the frustoconical sealing surface when the piston is biased into the closed position.

Claim 5

The invention as in claim 3 wherein the one member is the seat and the other member is the piston.

Claim 6

The invention as defined in claim 1 wherein the body is constructed of a multiplicity of individual molded parts including a lower barrel part having bosses defining a spaced pair of passages therein, an upper barrel valve case part having bosses defining a similarly spaced pair of passages therein, said case part joining with the barrel part to join the passages therein, and means for holding the parts joined together.

Claim 7

The invention as defined in claim 5 wherein the parts are joined together along adjacent edges, wherein the adjacent ends of the bosses are spaced from each other, and additionally comprising valves located between the adjacent ends of the bosses for controlling the flow of fluid through the passages.

Claim 8

The invention as defined in claim 6 wherein the edges are suitably notched so as to provide holes when joined together and wherein the valve includes valve seats on the adjacent ends of the passages, an apertured ball between each pair of valve seats, and a handle extending from each apertured ball through the respective holes to the outside of the body, manual rotation of the handle rotating the ball between an open position wherein the aperture is aligned between the adjacent ends of the passage and a closed position wherein the aperture is not aligned with the adjacent ends of the passage to regulate the flow therethrough.

Claim 9

The invention as in claim 1 wherein the body is constructed of a multiplicity of individually molded parts including a case part having the inlet and outlet passages formed therein as well as a portion of an interconnecting passage formed therein and opening to the inlet passage; a diaphragm housing part having a cavity therein and being suitably shaped for joining to the case part to close the cavity, said diaphragm housing part having formed therein the rest of the interconnecting passage which opens into the cavity and which joins with the portion thereof in the case part to fluidly connect the inlet passage to the cavity; a diaphragm support housing part received in the cavity of the diaphragm housing part, said support housing part dividing the cavity into the intermediate chamber and the diaphragm chamber, said support housing part mounting the diaphragm to divide the diaphragm chamber into the inlet pressure portion into which the interconnecting passage opens, and the intermediate pressure portion, said support housing part having the exhaust passage therein and the relief valve mounted thereto with the resilient connecting means being located between the relief valve and the diaphragm; and means for holding the parts together.

Claim 10

The invention as in claim 8 wherein the diaphragm housing part includes a portion of the interconnecting passage which opens into the cavity and includes a tubular member therein which extends between the diaphragm housing part portion and the case part portion to fluidly connect the portions in the two parts.

Claim 11

The invention as in claim 8 wherein the check valves are located in the inlet and outlet passages and are secured to the case part, and wherein one of said valves has a protruding post which engages the diaphragm support housing part to define and buttress the closed position of the valve.

Claim 12

The invention as in claim 8 wherein the parts additionally include a lower barrel part suitably shaped for joining to the case part, and wherein the holding means includes a first set of holding elements for holding the barrel part, the case part and the diaphragm housing part together and a second set of holding elements for holding the case part and the diaphragm housing part together to aid the first set to withstand the higher pressures expected between the case part and the diaphragm housing part.

Claim 13

In a back flow valve, including a body having an inlet passage for connection to a source of fluid; an intermediate chamber fluidly connected to the inlet passage via an inlet check valve; an oUtlet passage fluidly connected to the intermediate chamber via an outlet check valve and for connection to a receiver of fluid; an exhaust passage fluidly connected to the intermediate chamber via a relief valve, and opening to atmosphere; a diaphragm in the diaphragm chamber dividing the diaphragm chamber into an inlet pressure portion and an intermediate pressure portion, said inlet pressure portion being fluidly connected to the inlet passage and said intermediate pressure portion being fluidly connected to the intermediate chamber; and means for connecting the relief valve and the diaphragm together, the improvement comprising the provision of a body constructed of a multiplicity of individual molded parts including a case part having the inlet and outlet passages formed therein as well as a portion of an interconnecting passage formed therein and opening to the inlet passage; a diaphragm housing part having a cavity therein and being suitably shaped for joining to the case part to close the cavity, said diaphragm housing part having formed therein the rest of the interconnecting passage which opens into the cavity and which joins with the portion thereof in the case part to fluidly connect the inlet passage to the cavity; a diaphragm support housing part received in the cavity of the diaphragm housing part, said support housing part dividing the cavity into the intermediate chamber and the diaphragm chamber, said support housing part mounting the diaphragm to divide the diaphragm chamber into the inlet pressure portion into which the interconnecting passage opens, and the intermediate pressure portion, said support housing part having the exhaust passage therein and the relief valve mounted thereto; and means for holding the parts together.

Claim 14

In a back flow valve, including a body having an inlet passage for connection to a source of fluid; an intermediate chamber fluidly connected to the inlet passage via an inlet check valve; an oUtlet passage fluidly connected to the intermediate chamber via an outlet check valve and for connection to a receiver of fluid; an exhaust passage fluidly connected to the intermediate chamber via a relief valve, and opening to atmosphere; a diaphragm in the diaphragm chamber dividing the diaphragm chamber into an inlet pressure portion and an intermediate pressure portion, said inlet pressure portion being fluidly connected to the inlet passage and said intermediate pressure portion being fluidly connected to the intermediate chamber; and means for connecting the relief valve and the diaphragm together, the improvement comprising the provision of a body constructed of a multiplicity of individual molded parts including a case part having the inlet and outlet passages formed therein as well as a portion of an interconnecting passage formed therein and opening to the inlet passage; a diaphragm housing part having a cavity therein and being suitably shaped for joining to the case part to close the cavity, said diaphragm housing part having formed therein the rest of the interconnecting passage which opens into the cavity and which joins with the portion thereof in the case part to fluidly connect the inlet passage to the cavity; a diaphragm support housing part received in the cavity of the diaphragm housing part, said support housing part dividing the cavity into the intermediate chamber and the diaphragm chamber, said support housing part mounting the diaphragm to divide the diaphragm chamber into the inlet pressure portion into which the interconnecting passage opens, and the intermediate pressure portion, said support housing part having the exhaust passage therein and the relief valve mounted thereto; and means for holding the parts together.

Claim 15

The invention as in claim 12 wherein the diaphragm housing part includes a portion of the interconnecting passage which opens into the cavity and includes a tubular member therein which extends between the diaphragm housing part portion and the case part portion to fluidly connect the portions in the two parts.

Claim 16

The invention as in claim 12 wherein the check valves are located in the inlet and outlet passages and as secured to the case part, and wherein one of said valves has a protruding post which engages the diaphragm support housing part to buttress the closed position of the valve.

Claim 17

The invention as in claim 12 wherein the parts additionally include a lower barrel part suitably shaped for joining to the case part, and wherein the holding means includes a first set of holding elements for holding the barrel part, the case part and the diaphragm housing part together and a second set of holding elements for holding the case part and the diaphragm housing part together to aid the first set to withstand the higher pressures expected between the case part and the diaphragm housing part.

Claim 18

The invention as defined in claim 12 wherein the parts additionally include a lower barrel part having bosses defining a spaced pair of passages therein, and wherein the upper barrel valve case part has similarly spaced bosses defining a pair of passages therein, said case part joining with the barrel part to join the passages therein.

Claim 19

The invention as defined in claim 16 wherein parts are joined together along adjacent edges, wherein the adjacent ends of the bosses are spaced from each other, and additionally comprising valves located between the adjacent ends of the bosses for controlling the flow of fluid through the passages.

Claim 20

The invention as defined in claim 17 wherein the edges are suitably notched so as together to provide holes, and wherein the valve includes valve seats on the adjacent ends of the passages, and apertured ball between each pair of the valve seats, and a handle extending from each apertured ball through the respective hole to the outside of the body, manual rotation of the handle rotating the ball between an open position wherein the aperture is aligned between the adjacent ends of The passage and a closed position wherein the aperture is not aligned with the adjacent ends of the passages to regulate the flow therethrough.

Claim 21

The invention as in claim 12 wherein at least one of the check valves comprises a valve seat member on the body and having a piston receiving opening therein, a valve piston member mounted on the body for movement relative the seat member between open and closed positions, means for biasing the piston member to the closed position in the opening on the seat member, one of said members having a frustoconical sealing surface adjacent the other member, the other said members having a sealing ring receiving groove opening generally toward the sealing surface and a sealing ring in said groove for wedging sealing engagement with the frustoconical sealing surface when the piston is biased into the closed position.

Claim 22

The invention as in claim 12 wherein the means for connecting the relief valve to the diaphragm include, spring means with one end attached to the relief valve and the other end attached to the diaphragm, said spring means changing its length upon slight changes in the fluid pressure in the valve to hold the relief valve closed and thereby prevent these slight pressure changes from causing fluid to spit into the exhaust passages.

Claim 23

A check valve for a valve body comprising a valve seat member on the body and having a piston receiving opening therein, a valve piston member mounted on the body for movement relative the seat member between open and closed positions, means for biasing the piston member to the closed position in the opening on the seat member, one of said members having a frustoconical sealing surface adjacent the other member, the other of said members having a sealing ring receiving groove opening generally toward the sealing surface, and a sealing ring in said groove for wedging sealing engagement with the frustoconical sealing surface when the piston is biased into the closed position.

Claim 24

A check valve for a valve body comprising a valve seat member on the body and having a piston receiving opening therein, a valve piston member mounted on the body for movement relative the seat member between open and closed positions, means for biasing the piston member to the closed position in the opening on the seat member, one of said members having a frustoconical sealing surface adjacent the other member, the other of said members having a sealing ring receiving groove opening generally toward the sealing surface, and a sealing ring in said groove for wedging sealing engagement with the frustoconical sealing surface when the piston is biased into the closed position.

Claim 25

In a backflow preventing valve including an inlet passage, an outlet passage, an intermediate passage between the inlet and outlet passages, a relief valve selectively venting the intermediate passage to atmosphere, and a diaphragm with inlet pressure supplied to one side thereof and with intermediate passage pressure supplied to the other side thereof, the improvement comprising the provision of a resilient connecting means between the diaphragm and the relief valve for operably connecting the relief valve to the diaphragm while allowing slight relative movement therebetween, whereby upon variations of fluid pressure, the diaphragm can flex slightly without moving the relief valve, but upon a leak of fluid from the outlet passage into the intermediate passage, said diaphragm will flex beyond the limited amount allowed to move the resilient connecting means and cause the relief valve to open and exhaust the excess fluid to avoid possibly contaminating the fluid supply.

Claim 26

In a backflow preventing valve including an inlet passage, an outlet passage, an intermediate passage between the inlet and outlet passages, a relief valve selectively venting the intermediate passage to atmosphere, and a diaphragm with inlet pressure supplied to one side thereof and with intermediate passage pressure supplied to the other side thereof, the improvement comprising the provision of a resilient connecting means between the diaphragm and the relief valve for operably connecting the relief valve to the diaphragm while allowing slight relative movement therebetween, whereby upon variations of fluid pressure, the diaphragm can flex slightly without moving the relief valve, but upon a leak of fluid from the outlet passage into the intermediate passage, said diaphragm will flex beyond the limited amount allowed to move the resilient connecting means and cause the relief valve to open and exhaust the excess fluid to avoid possibly contaminating the fluid supply.