FAQ: General Technical

Blackmer FAQ: General Technical

• What application information is important when specifying a pump?

  Fluid properties, like viscosity, temperature, specific gravity, chemical compatibility, abrasiveness, are all important to know when specifying a pump. This will be important in identifying the materials of construction and the performance characteristics necessary to make the pump work in the application.

  System properties, like desired flow rate, pressure differential, location, certifications, NPSHa, are all important to when specifying a pump. These properties will identify the size and power requirements of the pump needed to perform in the application.

• What is a PD pump and what does it do?

  PD stands for positive displacement, and by definition, positive displacement (PD) pumps displace a known quantity of liquid with each revolution of the pumping components (vanes in the case of Blackmer Sliding Vane Pumps). PD pumps displace liquid by creating a space between the pumping components and trapping liquid in the space. The rotation of the pumping components then reduces the size of the space and moves the liquid out of the pump.

• What is a self-priming pump?

  Self-priming allows a sliding vane pump to draw a suction vacuum and compress air into the discharge piping, all while dry running. This enables the pump to be used in applications with offload suction-lift installations or with long sections of suction pipe. The self-priming feature is an inherent benefit of sliding vane pumps.

• What paint is used to coat Blackmer pumps?

  Blackmer pumps are coated in a Tile-Clad High solids coating from Sherwin Williams. Applications are rated for marine environments. Preparation of this coating includes an epoxy primer and 3 layers of gloss and EG-shel hardeners. Signature Blackmer blue coating comes standard on all Blackmer Sliding Vane Pumps. If required, other colors are available for an additional cost.

• Are FKM elastomers compatible with ethanol?

  Yes. Although FKM is not typically compatible with ethanol, Blackmer has upgraded its FKM elastomers to a high-grade FKM compound. This compound is compatible with ultra-low sulfur diesel and all ethanol and biodiesel blends.

• What is the temperature rating of Blackmer Sliding Vane Pumps?

  Temperature limitations of sliding vane pumps vary from series to series and from elastomer to elastomer. The appropriate temperature rating for each pump can be found on the pump product page on the website, materials of construction document or in the Blackmer material compatibility guide.

• What is the noise rating of Blackmer Sliding Vane Pumps?

  Sound pressure levels for Blackmer Sliding Vane Pumps typically does not exceed 85 dBA.

• Are there published NPSHr curves for Blackmer Sliding Vane Pumps?

  NPSH stands for “Net Positive Suction Head”.  Piping systems provide available NPSH, which is a measure of pressure allowance provided by the system that exceeds the liquid vapor pressure.  In many applications, designers and engineers target pumps that have required NPSH (or NPSHR) that is less than the system’s available NPSHA.  (Making sure the pump consumes less NPSH than is provided by the system). 

  NPSHA vs. NPSHR comparisons are especially important for technologies that are poorly equipped to process multiphase mixtures, like typical ANSI centrifugal pumps and internal gear pumps.  Blackmer rotary vane pumps are well equipped to process vapor/liquid mixtures, even up to 40% mixtures.  As such, Blackmer does not publish NPSHR because we anticipate systems that have zero or low available NPSH.  NPSHA vs. NPSHR is not a constructive acceptance criteria for Blackmer rotary vane pumps.  In fact, we have the industries only 2-year guarantee on our cavitation series pumps, because we are so confident in our cavitation suppression technology.  Please refer to our cavitation suppression technology link for more information.

• What Industry pump standards does Blackmer follow?

  Blackmer Sliding Vane Pumps are tested to ANSI HI 6.1 for rotary positive displacement. The ANSI HI 6.1 standard lists testing requirements for all rotary positive displacement pumps including vane pumps, gear pumps, lobe pumps, etc.

• How do I obtain more information for the motors and gearboxes used on Blackmer provided unit assemblies?

  Using the Blackmer price pages, distributors can search the Blackmer part number and correspond the part to the supplier catalog numbers. This catalog number can be used to gather more information at the manufacturer's website.

• How do I know what the configuration string of the pump represents?

  Each pump model is represented by 15-20 character configuration code. The code represents various components on the pump including pump vane types, seal types, and shaft type. To decode the configuration string, reference Blackmer technical document 001-030.

• I need technical product support. Who should I contact?

  Please contact your local distributor for technical systems questions and general troubleshooting. Additionally, you can also contact Blackmer for technical questions about our pumps and compressors at pumphelp@blackmer.com.
  

• How do I determine what material a part is made of?

  Each Blackmer pump and compressor model has a material compatibility document associated with it. All material compatibility guides (MOC) documents are available here: https://www.psgdover.com/blackmer/download-library/materials-of-construction-(moc) or on the specific product page for the pump or compressor.
  

• Do you provide training for any of your products?

  Training materials on all Blackmer products, including manuals and videos, are available on the Blackmer website, in our Training Materials section.
  

• What is NPSHr of Blackmer Sliding Vane Pumps for liquefied gases?

  NPSH questions are common, because NPSHr vs. NPSHa is a common acceptance criteria for pumps. 

  • NPSHa is an allowance provided by the system.
  • NPSHr is an absolute pressure measurement and corresponds to a pump’s mechanical efficiency at 95% of the design flow rate.
  • In theory, if NPSHa > NPSHr, cavitation is limited within a pump.

  For high vapor pressure fluids and liquefied gases (i.e. propane, condensate, etc), a NPSH comparison is not applicable because these fluids are a multiphase mixture of liquid and gas.  Vapor is always present in these systems, making cavitation unavoidable.  Instead, the appropriate criteria is includes limited pressure loss within suction piping, maximum withdraw rate relative to size of source vessel and additional constraints detailed in the Blackmer Liquified Gas Handbook (500-001).
  
  

  Blackmer Cavitation Series Sliding Vane Pumps (CRL, LGL, SGL) are well suited for operation under continuous cavitation and vapor/liquid mixtures.

  • The Cavitation Series Vane Pumps leverage the unique cavitation suppression technology of Blackmer. This video and white paper provide more information.
  • The LGL Series Vane Pumps are backed by an unconditional 2-year performance assurance guarantee, underscoring our confidence in operating under continuous cavitation.
  • A comprehensive guide to pumping LPG is provided in the Blackmer Liquified Gas Handbook (500-001).

  In summary, an NPSH comparison is useful for the proper selection of pumps to avoid excessive cavitation.  However an NPSH comparison should not be used as acceptance criteria for applications where vapor is expected regardless of the NPSHa condition. 

  
  

• What does the final letter character shown on Blackmer Vane Pump models mean?

  The final alpha character shown on Blackmer Vane Pumps models signifies what revision the pump is. For example the pump model of TLGLF3C,  the "C" indicates that there are three revisions on this pump - A, B and C, and C is the most recent.
  
  

  When comparing compatibility between model revisions:

  • If the component part numbers are the same, then the parts are interchangeable between revisions. 
  • If the component part numbers are different, then parts are not interchangeable between revisions.
  • We do not have a revision summary that describes differences between revisions.

• Why is NPSH testing not offered for Blackmer Gear Pumps?

  NPSH testing is done with water which is below the minimum recommended viscosity for use with internal gear pumps.  Though testing is only done for a short period, it may cause additional fatigue and wear resulting in lower life expectancy of pumping chamber components.  If NSPH testing is absolutely required, we will need to discuss it with our engineering team to develop a plan to support your application.