A method of constructing a plate fin heat exchanger includes joining a first side bar formed from a nickel-iron alloy to a first end of a fin element formed from a nickel-iron alloy through a first nickel-iron alloy bond, and joining a second side bar formed from a nickel-iron alloy to a second end of the fin element through a second nickel-iron alloy bond to create a first layer of the plate fin heat exchanger. The fin element defines a fluid passage.

A method of constructing a plate fin heat exchanger includes joining a first side bar formed from a nickel-iron alloy to a first end of a fin element formed from a nickel-iron alloy through a first nickel-iron alloy bond, and joining a second side bar formed from a nickel-iron alloy to a second end of the fin element through a second nickel-iron alloy bond to create a first layer of the plate fin heat exchanger. The fin element defines a fluid passage.

A piston rod seal unit. The piston rod seal unit includes a housing, a cylinder gland, and at least one floating rod seal assembly mounted in the cylinder gland, the floating rod seal assembly comprising at least one rod seal mounted onto the floating rod seal assembly.

A piston rod seal unit. The piston rod seal unit includes a housing, a cylinder gland, and at least one floating rod seal assembly mounted in the cylinder gland, the floating rod seal assembly comprising at least one rod seal mounted onto the floating rod seal assembly.

A shell-and-tube heat exchanger with externally-connected tube chambers includes a tube sheet, a shell, heat exchanging tubes, an inlet externally-connected tube chamber, and an outlet externally-connected tube chamber, wherein: the inlet and outlet externally-connected tube chambers are respectively fixed to corresponding positions of the tube sheet, two flow guiding devices are respectively located in the inlet and outlet externally-connected tube chambers, the two flow guiding devices respectively have two cavities therein, multiple flow guide channels outwardly extend from the cavities to the tube sheet and communicated with the tube sheet; one cavity of the outlet externally-connected tube chamber is communicated with a tube side outlet pipe, and one cavity of the inlet externally-connected tube chamber is communicated with a tube side inlet pipe. The shell-and-tube heat exchanger is reasonable in design, can effectively improve the sealing performance and reduce the tube side pressure drop, and has broad application prospects.

A shell-and-tube heat exchanger with externally-connected tube chambers includes a tube sheet, a shell, heat exchanging tubes, an inlet externally-connected tube chamber, and an outlet externally-connected tube chamber, wherein: the inlet and outlet externally-connected tube chambers are respectively fixed to corresponding positions of the tube sheet, two flow guiding devices are respectively located in the inlet and outlet externally-connected tube chambers, the two flow guiding devices respectively have two cavities therein, multiple flow guide channels outwardly extend from the cavities to the tube sheet and communicated with the tube sheet; one cavity of the outlet externally-connected tube chamber is communicated with a tube side outlet pipe, and one cavity of the inlet externally-connected tube chamber is communicated with a tube side inlet pipe. The shell-and-tube heat exchanger is reasonable in design, can effectively improve the sealing performance and reduce the tube side pressure drop, and has broad application prospects.

A shell-and-tube heat exchanger with distributed inlet-outlets includes a shell, heat exchanging tubes, a tube plate, an outlet fluid distribution device and an inlet fluid distribution device. Each of the inlet and outlet fluid distribution devices includes a tube side connecting pipe and at least one bell-shaped tube. A fine end of the bell-shaped tube is connected with the tube side connecting pipe, the tube side connecting pipe passes through the tube plate, a magnifying sealing plate is installed at a magnifying end of the bell-shaped tube, the magnifying sealing plate has circular holes respectively corresponding to the heat exchanging tubes, the heat exchanging tubes are respectively installed within the circular holes of the magnifying sealing plate and communicated with an interior of the bell-shaped tube. The shell-and-tube heat exchanger is reasonable in design, strong in practicality and simple in preparation process, so that it has broad application prospects.

A shell-and-tube heat exchanger with distributed inlet-outlets includes a shell, heat exchanging tubes, a tube plate, an outlet fluid distribution device and an inlet fluid distribution device. Each of the inlet and outlet fluid distribution devices includes a tube side connecting pipe and at least one bell-shaped tube. A fine end of the bell-shaped tube is connected with the tube side connecting pipe, the tube side connecting pipe passes through the tube plate, a magnifying sealing plate is installed at a magnifying end of the bell-shaped tube, the magnifying sealing plate has circular holes respectively corresponding to the heat exchanging tubes, the heat exchanging tubes are respectively installed within the circular holes of the magnifying sealing plate and communicated with an interior of the bell-shaped tube. The shell-and-tube heat exchanger is reasonable in design, strong in practicality and simple in preparation process, so that it has broad application prospects.

Low head loss systems are detailed. The systems may include chambers having low impedance to water flow therethrough and repositionable gates or other valves within the chambers. The valves may direct water as a function of whether an associated heating device is active. At least some gates may incorporate poppet valves or other high-flow by-passes.

A device heating a fluid and usable in a rocket launcher to pressurize a liquefied propellant. The device includes a first burner performing first combustion between a limiting propellant and an excess propellant; a first heat exchanger in which first burnt gas from the first combustion transfers heat to the fluid; at least one second burner into which both the first burnt gas and some limiting propellant are injected to perform second combustion between the limiting propellant and at least a portion of unburnt excess propellant present in the first burnt gas. The second burnt gas from the second combustion flows through a second heat exchanger to transfer heat to the fluid. Burnt gas from each combustion flows in respective burnt gas tubes within a common overall heat exchanger including the heat exchange units, the gas transferring heat to the fluid, the fluid flowing between the burnt gas tubes.