Controlling and delivering gases in a plasma arc torch and related systems and methods

1. A torch receptacle for coupling a plasma arc torch to a torch lead of a plasma cutting system, the torch receptacle comprising:

a body having a first end shaped to connect to the torch lead and a second end shaped to connect to a torch body or a torch tip of the plasma arc torch;

a pair of entry ports disposed at the first end of the body and configured to fluidly connect to a set of fluid conduits disposed within the torch lead; and

a multiway valve having at least two inlets and an outlet disposed within the body and fluidly connected to the pair of entry ports at the first end of the body and to a torch gas conduit disposed at the second end of the body, the multiway valve being configured to select between a first plasma gas and a second plasma gas entering the pair of entry ports by selectively blocking a flow of either the first plasma gas or the second plasma gas entering the body, thereby delivering a selected plasma gas through the torch body to the torch gas conduit to supply the plasma arc torch.

2. The torch receptacle of claim 1 wherein the body is formed of a substantially insulative material.

3. The torch receptacle of claim 1 wherein the body has a length of less than about 1 foot between the first end and the second end.

4. The torch receptacle of claim 1 wherein the multiway valve is a three-way valve fluidly coupled to a first conduit of the set of fluid conduits, a second conduit of the set of fluid conduits, and the torch gas conduit and is configured to select gas from either the first conduit or the second conduit and permit delivery of the selected gas to the torch body via the torch gas conduit.

5. The torch receptacle of claim 1 wherein the body defines a set of fluid flow paths disposed substantially within the body to fluidly couple the multiway valve to the fluid conduits within the torch lead.

6. The torch receptacle of claim 1 wherein the multiway valve is located less than 12 inches from a plasma plenum of the plasma arc torch.

7. The torch receptacle of claim 1 wherein the pair of entry ports comprises a first plasma gas entry port and a second plasma gas entry port, the first plasma gas port being configured to receive a plasma pre-flow gas and the second plasma gas port being configured to receive a plasma cut flow gas.

8. The torch receptacle of claim 1 wherein the torch gas conduit has a volume of less than about 0.3 cubic inches.

9. The torch receptacle of claim 8 wherein the torch gas conduit has a volume of less than about 0.2 cubic inches.

10. The torch receptacle of claim 1 wherein the torch lead fluidly couples at least one of the set of conduits to vented atmospheric pressure.

11. The torch receptacle of claim 10 wherein an excess of plasma gas blocked from entering the torch gas conduit by the multiway valve is vented upstream through the torch lead.

12. The torch receptacle of claim 1 wherein the multiway valve is configured to switch a supply of gas provided to the torch body via the torch gas conduit between gases entering the pair of entry ports.

13. The torch receptacle of claim 1 comprising a shield gas port fluidly connected to a shield gas conduit formed between the first end of the body and the second end of the body.

14. A plasma arc torch system comprising:

a plasma torch power supply comprising:

a set of gas supplies comprising a first plasma gas and a second plasma gas;

a torch lead manifold to fluidly connect the set of gas supplies to the plasma torch lead line; and

a vent valve to vent at least one of the first plasma gas and the second plasma gas to atmospheric pressure;

a plasma torch lead line configured to couple to the torch lead manifold, the plasma torch lead line defining a set of fluid passages to convey the first plasma gas and the second plasma gas from the plasma torch power supply; and

a torch receptacle for coupling a plasma arc torch to the plasma torch power supply, the torch receptacle comprising:

a body having a first end to couple to the plasma torch lead line and a second end shaped to connect to a torch body or a torch tip of the plasma arc torch;

a pair of entry ports defined at the first end of the body and configured to fluidly connect to the set of fluid passages of the plasma torch lead line; and

a multiway valve having at least two inlets and an outlet disposed within the body and fluidly connected to the pair of entry ports at the first end of the body, to be fluidly coupled to a first passage of the set of fluid passages in the plasma torch lead line and to a second passage of the set of fluid passages in the plasma torch lead line, and to a torch gas conduit formed in the second end of the body having a volume of less than about 0.3 cubic inches, the multiway valve being configured to select between a first plasma gas and a second plasma gas entering the pair of entry ports by selectively blocking a flow of either the first plasma gas or the second plasma gas entering the body, thereby delivering a selected plasma gas from either the first passage or the second passage through the torch body to the torch gas conduit to supply the plasma arc torch.

15. The torch receptacle of claim 1 wherein the multiway valve is configured to transition between a first plasma gas and a second plasma gas in less than about 1 second.

16. The plasma arc torch system of claim 14 wherein the multiway valve is configured to transition between a first plasma gas and a second plasma gas in less than about 1 second.

17. The plasma arc torch system of claim 14 wherein the multiway valve is located less than 12 inches from a plasma plenum of the plasma arc torch.