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Variable Speed Fire Pump Controllers were invented and released with a UL Listing for fire pump service in 2003 by Master Control Systems, Inc. [1] [2] Paragraph 10.5.5 in the 2003 edition of NFPA-20 recognized Variable Speed as an accepted method for operating the fire pump. Then in the NFPA-20 2007 edition, section 10.10 was added to clarify ...
In 1988, Pentair agreed to acquire FC Holdings Inc., the holding company for Federal Cartridge and Hoffman Engineering, for $175 million in cash and the assumption of debt. Pentair would not hold Federal Cartridge for a long time, but the purchase of Hoffman Engineering was the start of a prosperous era of enclosures manufacturing for Pentair.
Piston pumps can be made variable-displacement by inserting springs inline with the pistons. The displacement is not positively controlled, but decreases as back-pressure increases. Another variation is the variable-displacement vane pump, a type that has found usage in motor vehicle automatic transmissions, such as the General Motors Hydra-Matic.
The compressor may be driven by a variable speed or constant speed machine. If driven by a constant speed electric motor it may be controlled with variable inlet guide vanes or suction and discharge throttling. Welch [49] shows the effect of variable vane angle on the flow for a centrifugal compressor.
The affinity laws (also known as the "Fan Laws" or "Pump Laws") for pumps/fans are used in hydraulics, hydronics and/or HVAC to express the relationship between variables involved in pump or fan performance (such as head, volumetric flow rate, shaft speed) and power. They apply to pumps, fans, and hydraulic turbines. In these rotary implements ...
Small variable-frequency drive Chassis of above VFD (cover removed). A variable-frequency drive (VFD, or adjustable-frequency drive, adjustable-speed drive, variable-speed drive, AC drive, micro drive, inverter drive, variable voltage variable frequency drive, or drive) is a type of AC motor drive (system incorporating a motor) that controls speed and torque by varying the frequency of the ...
A 0.75 HP bore-well submersible pump which had been used to pump groundwater One style of submersible pump for industrial use. Outlet pipe and electrical cable not connected. A submersible pump (or electric submersible pump (ESP) is a device which has a hermetically sealed motor close-coupled to the pump body. The whole assembly is submerged in ...
A critical element in vane pump design is how the vanes are pushed into contact with the pump housing, and how the vane tips are machined at this very point. Several type of "lip" designs are used, and the main objective is to provide a tight seal between the inside of the housing and the vane, and at the same time to minimize wear and metal-to ...