What are the Vanes in Sliding Vane Pumps?

As the name implies, the feature that differentiates sliding vane pumps from other pumping technologies is, in fact, the pump’s vanes, much like a pair of flexible diaphragms is unique to air-operated double-diaphragm pumps and the presence of meshing gears define the operation of internal/external gear pumps.

Invented in 1899 by Robert M. Blackmer, the sliding vane pumping principle was a true revelation for the industry at the time. What Mr. Blackmer created was a new form of positive displacement (PD) pump, one that could produce a wide range of flow rates while remaining volumetrically consistent despite changes in pumping pressure, temperature and product viscosity, and even as the vanes would wear. Sliding vane pumps are also easier to service and maintain than other technologies, as the pump does not need to be taken offline when the vanes need to be replaced. These operational and maintenance advantages help make Blackmer® Sliding Vane Pumps a go-to technology for liquid-handling applications in a wide array of markets, including chemical, energy, transport, military, marine, oil and gas, and general industrial.

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How Do Sliding Vanes Function?

Learning the differences between various sliding vane materials requires understanding how vanes function within a Blackmer Sliding Vane Pump.

The sliding vanes are located in the slots in the center of the pump’s rotor. Each vane is rectangular and features two center grooves, a leading edge, a trailing edge and a wear plate. The wear plates protect the backside of the vane from contact with pump models that feature a pushrod, with not all Blackmer vane pump models requiring the use of pushrods.

Sliding vane pumps operate when the rotor begins turning and the sliding vanes draw the liquid in behind each vane through the inlet port and into the pumping chamber. As the rotor turns, the liquid is transferred between the vanes to the outlet port where it is discharged as the pumping chamber is squeezed down. As the rotor turns, each of the pump’s vanes provides a positive mechanical push to the liquid ahead of it.

Three physical forces maintain the vane contact with the wall of the pumping chamber: (1) centrifugal force from the rotor’s rotation, (2) pushrods moving between opposing pairs of vanes and (3) liquid pressure entering through the vane grooves and acting on the rear of the vanes.

Each revolution of a sliding vane pump displaces a constant volume of fluid with any variance in pressure having a minimal effect. In addition, any energy-wasting turbulence and slippage are minimized, and high volumetric efficiency is maintained even as the vanes wear.

What Are The Vane Materials?

The vanes used in Blackmer Sliding Vane Pumps are available in various materials of construction in order to better meet the demands of unique pumping applications. Having options in vane materials is essential because vane composition must be matched to the requirements of the pumping process and liquids being transferred. The vanes must be strong enough to withstand pressure stresses, along with centrifugal and mechanical pumping forces. Each application also demands compatibility with the pumped liquid and good wear properties that can deliver a long life of sustained and reliable vane performance.

Blackmer offers vanes composed of such compounds as Duravane, Enduravane, laminate, bronze, iron and carbon – with each vane material performing optimally in different conditions.

What Factors Affect Vane Materials?

While each vane model is engineered for adaptability and optimized performance, some construction materials handle the following factors differently:

  • Chemical compatibility
  • Viscosity
  • Temperature range
  • Lubrication properties of the fluid
  • Abrasives or suspended solids in the fluid
  • Cost of maintenance (You want the vanes to wear out first so that there is not damage to the pump cylinder or liner)

Types of Vane Materials and Characteristics

Material Composition Size Max. Temp. Viscosity Range Typical Usage
Duravane Plastic with Fibers STD 240°F (115°C) 0 - 20,000 SSU
(0 - 4,250 cSt)		 An economical, general purpose, self-lubricating vane with a wide chemical-compatibility range. Duravane has a proven track record of reliable performance in a wide range of difficult applications.
Enduravane Plastic with Fibers STD 240°F (115°C) 0 - 20,000 SSU
(0 - 4,250 cSt)		 Based on Duravane, but with a different blend of materials, Enduravane is a self-lubricating, wear-resistant vane for high-pressure applications.
Laminate Melamine
Formaldehyde
Resin/Fiber		 STD
EC*		 240°F (115°C)
400°F (204°C)		 0 - 20,000 SSU
(0 - 4,250 cSt)
0 - 40,000 SSU
(0 - 8,500 cSt)		 Excellent vane where added strength/wear resistance is required. Self-lubricating and abrasion-resistant.
Bronze ASTM B30-54-3A EC* 500°F (260°C) 500 - 500,000 SSU
(105 - 108.000 cSt)		 Used with viscous fluids and in elevated temperature applications.
Iron Cast Iron ASTM A48 Minimum Class 25 EC* 500°F (260°C) 500 - 500,000 SSU
(105 - 108.000 cSt)		 An economical vane for viscous fluids and elevated temperature applications.
Hardened Iron Heat Treated Cast Iron EC* 500°F (260°C) 500 - 500,000 SSU
(105 - 108.000 cSt)		 A wear-resistant vane for abrasive applications.
Carbon Impregnated Carbon STD 500°F (260°C) 0 - 20,000 SSU
(0 - 4,250 cSt)		 A chemically inert vane suitable for a wide range of fluids and temperature capabilities.
NOTE: Only use with up to 100-psi (689 kPa) maximum differential pressure. Carbon vanes will not tolerate cavitation or discharge spikes (hydraulic shock).

STD – Full-Size Vanes
EC – Extra-Clearance Vanes/Reduced Length
*EC – Extra Clearance refers to the vane length being slightly reduced. This is useful for high-temperature applications. Generally, the materials we use for vanes will expand more thermally than the rotor/cylinder/liner/case materials. This means that if there isn’t extra clearance, the vanes could extend to the point that they become wedged between the pump heads/discs.

Viscosity & Vanes

Metal vanes are useful (and sometimes required) for thick, viscous fluids. The heavier weight helps them push thick fluid through the vane slot. Additionally, the viscous forces on the vane can require higher strength than what plastic vanes can provide.

Metal vanes made of iron or bronze perform better for higher-viscosity fluid applications, while vanes in plastic materials (Duravane, Enduravane and laminate) operate better at viscosities below 4,250 cP.

Temperature & Vanes

Another factor to consider when choosing vanes is temperature. Laminate vanes can be used at higher temperatures (400°F/204ºC) and viscosities than Duravane (limited to 240°F/115ºC), but they cost more and come with some chemical-compatibility issues. While bronze, iron and hardened iron can achieve temperatures up to 500°F (260ºC), they start to differ in wear properties. For example bronze has slightly better wear properties than iron, but some applications don’t allow for bronze alloys. Additionally, the cost difference between the materials can be a point of consideration. Finally, although carbon vanes have temperature limits up to 500°F (260ºC) they tend to chip/fracture easily and are only available in Blackmer Hand Pumps.

Blackmer Vane Pumps and Available Vane Materials

Not all vane materials are available for each Blackmer Sliding Vane Pump Product Series. Many of our pumps are designed and optimized for certain applications and fluids. Therefore, our standard vane materials and available vane material options have been carefully vetted and approved by our team of experts.

 
Pumps Duravane Laminate Bronze Iron Hardened Iron Carbon Enduravane
CRL S
GNX S O
O
Hand Pump         S
HXL S O
HXLJ8 (model) O S
LGL S
MAGNES S O

O
ML S  O S
NP S O O O
SGL S O
SMVP S  
   
SNP S O      
STX S            
STX-DEF S          
SX S          
TX S      
TXV (models) O O S
X S O
O
X1 (model) S



XL 1.25 & 1.5 (models) S O

XL 2-4 (models) S O
O
XLW O S
S= Standard, O= Optional

Learn More

Additional questions about our chemical compatibility with Blackmer Sliding Vane Pumps can be found in our Chemical Compatibility Guide.

Have other questions about vanes? Reach out to us below.

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