A fluid pressure control device includes a switching valve configured to operate in conjunction with the control valve by the pilot pressure led through the pilot valve to switch work of the operation check valve. The switching valve includes a pilot chamber to which the pilot pressure is led, a spool that moves in accordance with the pilot pressure of the pilot chamber, a bias member that biases the spool in the valve closing direction, a collar detachably installed in the pilot chamber, and a piston slidably inserted into the collar, the piston being configured to receive the pilot pressure on a back surface thereof and give thrust force to the spool against bias force of the bias member.

An electronic expansion valve is provided, wherein a piston component and a valve needle component are located at the same side of a valve core seat. When refrigerant flows forwards, the piston component closes the bypass through hole, the refrigerant flows to a side of the vertical connecting pipe via the valve core valve port, and the valve needle component moves in the axial direction to regulate an opening of the valve core valve port. When the refrigerant flows reversely, the piston component moves upwards in the axial direction to open the bypass through hole, and the refrigerant flows to a side of the transverse connecting pipe via the bypass through hole. The electronic expansion valve ensures that the valve needle component seals the valve core valve port easily in a high pressure state when the refrigerant flows forwards, and reduces axial and radial dimensions of the valve seat.

A valve body with an integral bypass includes a primary valve body portion defining a primary bore extending through the primary valve body portion from a primary upstream end to a primary downstream end, the primary bore defining an axis, the primary bore including a primary upstream bore extending through the primary upstream end and a primary downstream bore extending through the primary downstream end, the primary valve body portion configured to house a valve member between the primary upstream bore and the primary downstream bore; and the bypass seamlessly integrated with the primary valve body portion, the bypass defining a bypass bore, the bypass bore including a bypass upstream bore and a bypass downstream bore, the bypass including a bypass valve body disposed between the bypass upstream bore and the bypass downstream bore.

A valve body includes a flange; and an identification tab disposed on the flange, the identification tab defining indicia. A pipe system includes a first flange; a second flange fastened to the first flange by a plurality of fasteners; and an identification tab disposed on the first flange, the identification tab defining indicia.

A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when solenoid is in an excitation state, opens inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in pilot pressure chamber, the pilot spool opening a bypass passage when input current value is less and closes bypass passage when input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from inlet to outlet port in accordance with the pilot pressure chamber's pilot pressure.

A solenoid flow control valve includes: an inlet passage that allows an inlet port to communicate with a pilot pressure chamber; an outlet passage that allows the pilot pressure chamber to communicate with an outlet port; a fixed restrictor provided on the outlet passage; a pilot spool that closes the inlet passage when a solenoid is in a non-excitation state, whereas when solenoid is in an excitation state, opens inlet passage at an opening degree corresponding to an input current value to generate a pilot pressure corresponding to the input current value in pilot pressure chamber, the pilot spool opening a bypass passage when input current value is less and closes bypass passage when input current value is greater than or equal to the predetermined value; and a main spool that controls a flow rate from inlet to outlet port in accordance with the pilot pressure chamber's pilot pressure.

A valve body with an integral bypass includes a primary valve body portion defining a primary bore extending through the primary valve body portion from a primary upstream end to a primary downstream end, the primary bore defining an axis, the primary bore including a primary upstream bore extending through the primary upstream end and a primary downstream bore extending through the primary downstream end, the primary valve body portion configured to house a valve member between the primary upstream bore and the primary downstream bore; and the bypass seamlessly integrated with the primary valve body portion, the bypass defining a bypass bore, the bypass bore including a bypass upstream bore and a bypass downstream bore, the bypass including a bypass valve body disposed between the bypass upstream bore and the bypass downstream bore.

A valve body includes a flange; and an identification tab disposed on the flange, the identification tab defining indicia. A pipe system includes a first flange; a second flange fastened to the first flange by a plurality of fasteners; and an identification tab disposed on the first flange, the identification tab defining indicia.

A valve body with an integral bypass includes a primary valve body portion defining a primary internal surface, the primary internal surface defining a primary bore extending through the primary valve body portion from a primary upstream end to a primary downstream end; and the bypass seamlessly integrated with the primary valve body portion, the bypass defining a bypass internal surface, the bypass internal surface defining a bypass bore, the bypass bore comprising a bypass upstream bore and a bypass downstream bore, the bypass upstream bore extending through the primary upstream end of the primary valve body portion, the bypass downstream bore extending through the primary downstream end of the primary valve body portion, the bypass internal surface seamlessly intersecting the primary internal surface at the primary upstream end and the primary downstream end.

The present application relates to a switching valve, a switching hydraulic system, and a crane, in which the switching valve having an oil inlet and an oil outlet comprises at least two pairs of valve oil ports, a pair of cartridge valves provided between each pair of valve oil ports, and the oil inlet and the oil outlet are controlled such that the oil inlet and the oil outlet are capable of shifting between communications with the at least two pairs of valve oil ports. The switching valve switches on and off communication between the oil inlet and the oil outlet and the at least two pairs of valve oil ports by controlling opening or closing of the cartridge valves.