摘要:
A pipeline pig includes a venturi and a modulating valve located rearward of the inlet side of the venturi. When the valve is in the open position, a predetermined maximum bypass flow is allowed through the venturi. The closed position allows a predetermined minimum bypass flow. The valve may be a poppet-style valve or a frusto-conical shaped stopper. The stopper has sufficient mass and/or aerodynamic drag to overcome the spring force holding the valve in the open position. When the pig stalls, the valve closes and the stopper chokes bypass flow through the venturi. When the pig starts running again, the valve opens as inertia forces the stopper away from the inlet side of the venturi. Also, as friction of the pig increases due to changes in the internal diameter of the pipeline or accumulation of debris ahead of the pig, increased airflow across the valve creates drag sufficient to partially overcome the spring force, thus keeping the pig moving at a desirable rate of travel.
摘要:
A pipeline pig includes a venturi and a modulating valve located rearward of the inlet side of the venturi. When the valve is in the open position, a predetermined maximum bypass flow is allowed through the venturi. The closed position allows a predetermined minimum bypass flow. The valve may be a poppet-style valve or a frusto-conical shaped stopper. The stopper has sufficient mass and/or aerodynamic drag to overcome the spring force holding the valve in the open position. When the pig stalls, the valve closes and the stopper chokes bypass flow through the venturi. When the pig starts running again, the valve opens as inertia forces the stopper away from the inlet side of the venturi. Also, as friction of the pig increases due to changes in the internal diameter of the pipeline or accumulation of debris ahead of the pig, increased airflow across the valve creates drag sufficient to partially overcome the spring force, thus keeping the pig moving at a desirable rate of travel.
摘要:
A method and system for launching a pipeline pig includes the steps of compressing a modulating bypass valve of a pipeline pig and installing a locking means to temporally maintain the bypass valve in the compressed state. Once the pig has travelled a predetermined distance through the pipeline, the locking means is released and retrieved through the launch trap door. The locking means is preferably a launching pin having a clip attachment that receives the clips of a retractable lead. The lead is housed by a retraction device that is detachably secured to the launch trap door. The modulating valve has sufficient mass and aerodynamic drag to overcome the force of a gas spring. The valve moves between a retracted and compressed position substantially instantaneously upon the pipeline pig stalling and between the compressed and retracted position substantially instantaneously upon the pipeline pig accelerating.
摘要:
A method and system for launching a pipeline pig includes the steps of compressing a modulating bypass valve of a pipeline pig and installing a locking means to temporally maintain the bypass valve in the compressed state. Once the pig has travelled a predetermined distance through the pipeline, the locking means is released and retrieved through the launch trap door. The locking means is preferably a launching pin having a clip attachment that receives the clips of a retractable lead. The lead is housed by a retraction device that is detachably secured to the launch trap door. The modulating valve has sufficient mass and aerodynamic drag to overcome the force of a gas spring. The valve moves between a retracted and compressed position substantially instantaneously upon the pipeline pig stalling and between the compressed and retracted position substantially instantaneously upon the pipeline pig accelerating.
摘要:
A closure device includes a door carrying a series of interconnected shear blocks and a keystone shear block designed to transfer stresses created by pressure acting on the door to a surrounding hub. Each interconnected shear block has a limited rotation relative to its adjacent blocks. A holding band operating handle is in communication with a driving link which, in turn, is in communication with the keystone shear block. Actuating the handle causes the keystone shear block to move in an upward vertical direction. The linear movement of the keystone shear block allows the limited rotation of the interconnected shear blocks to occur, thereby causing the circumferential holding band to collapse within itself from an expanded-engaged position to a contracted-removed position relative to said hub. A pressure warning lock provides a safety device and prevents actuation of the holding band operating handle when the pressure chamber is under pressure.
摘要:
A closure device includes a door carrying a series of interconnected shear blocks and a keystone shear block designed to transfer stresses created by pressure acting on the door to a surrounding hub. Each interconnected shear block has a limited rotation relative to its adjacent blocks. A holding band operating handle is in communication with a driving link which, in turn, is in communication with the keystone shear block. Actuating the handle causes the keystone shear block to move in an upward vertical direction. The linear movement of the keystone shear block allows the limited rotation of the interconnected shear blocks to occur, thereby causing the circumferential holding band to collapse within itself from an expanded-engaged position to a contracted-removed position relative to said hub. A pressure warning lock provides a safety device and prevents actuation of the holding band operating handle when the pressure chamber is under pressure.
摘要:
A multi-function Pilates exercise apparatus featuring a foldable frame (200-203), a counterbalance mechanism (271), a wheeled base (90), a rotatable pulley riser with a flexible pulley mount (112), gear changing apparatus (FIG. 9) and adjustable footbar (471). The frame is designed to fold into an upright position and to be rolled to a desired location. The pulley assemblies may be rotated and positioned below the carriage rails. The gear changing apparatus permits the user to adjust the carriage position with a single handed operation. The exercise system includes a reformer, a pole apparatus, and mat mode including a long/short box.
摘要:
A multi-function Pilates exercise apparatus featuring a foldable frame, a counterbalance mechanism, a wheeled base, a rotatable pulley riser with a flexible pulley mount, gear changing apparatus and adjustable footbar. The frame is designed to fold into an upright position and to be rolled to a desired location. The pulley assemblies may be rotated and positioned below the carriage rails. The gear changing apparatus permits the user to adjust the carriage position with a single handed operation. The exercise system includes a reformer, a pole apparatus, and mat mode including a long/short box.
摘要:
A multi-function Pilates exercise apparatus featuring a foldable frame (200-203), a counterbalance mechanism (271), a wheeled base (90), a rotatable pulley riser with a flexible pulley mount (112), gear changing apparatus (FIG. 9) and adjustable footbar (471). The frame is designed to fold into an upright position and to be rolled to a desired location. The pulley assemblies may be rotated and positioned below the carriage rails. The gear changing apparatus permits the user to adjust the carriage position with a single handed operation. The exercise system includes a reformer, a pole apparatus, and mat mode including a long/short box.