Back in January, IMT Fluid & Gas Flow Journal reported on the debut of Blackmer’s NPH4F general-purpose sliding vane pump. This time, we get a better glimpse of the pump from Scott Jackson, product manager for the Americas for Blackmer.
According to Jackson, the NPH4F pump can be used in applications spanning from thin to thick viscosities and low to high temperatures. The pump can find itself in applications ranging from food processing to energy to construction, as the variety of fluids that might be handled by the pump include oils (lube oil, vegetable oil, etc), refined fuels, greases, adhesives, glues, resins, waxes, asphalt (bitumen), sugar, honey, syrups, molasses, chocolate, chemicals, solvents, beverages, and flavorings.
Since hot oil, steam or electric heating of asphalt, molasses, and some resins require jacketed pumps, a jacketed pump option for the NPH4F is also available.
Maximum versatility is the primary selling point of the positive-displacement pump specifically designed for fluid processing and transfer with a wide range of clean, non-corrosive fluids. Blackmer, based in Grand Rapids, Mich., also makes centrifugal pumps and reciprocating compressors.
The internal sleeve bearing pump comes standard with shaft packing and feature 180-deg ports, which is a distinction from the 90-deg ports of its NP4F predecessor. Says Jackson, “180-deg ports are commonly used and preferred in many industrial applications as they make for easier piping installation. It does require some adjustment in relief valve position and operation, but these modifications can be engineered [into the pump] without too much trouble.”
The NPH4F features ductile iron construction and an internal relief valve that protects against excessive pressures, ensuring operation under severe service conditions. The pump is capable of operating under pressures up to 200 psi (13.8 bar) and temperatures up to 500°F (260°C). Maximum pump speed is 500 rpm, whereby it achieves a maximum output of 525 gal/min (1,985 L/min).
Blackmer also offers optional cartridge mechanical seal, lip seal, or triple-lip cartridge seal over the standard shaft packing, as well as 4-inch weld and 4-inch ANSI 150# RF compatible or 4-inch NPT flanges. Standard shaft packing is designed to leak to provide lubrication to the pump shaft, but in many applications, any leakage is considered unacceptable. “In such applications, other sealing methods are preferred to ensure better sealing,” Jackson says.
Each sealing method has its own advantages and disadvantages. “Typically, the sealing progression is shaft packing first, while lip seals would be considered a step up,” Jackson explains. “Then, triple lip seals and finally cartridge mechanical seals provide increasing levels of sealing, although triple lip seals are often the most expensive option.” He says pump users can consider the variety of available cartridge mechanical seals.