Measuring Your Pump
Which information is needed in order to upgrade your pump to DuPont™ Vespel® CR-6100?
Using Vespel® CR-6100 wear parts with reduced clearance can help your pumps be more reliable, efficient, and easier to operate. Which measurements and which process data do we need to assemble for the upgrade?
Dimensions Needed for a Quote
Let’s start with the 3 dimensions we need to determine material sizes and availability shown in Figure 1:
- “R” Outside diameter of the rotor running against the Vespel® CR-6100
- “B” Inside diameter of the bore the Vespel® CR-6100 will press into
- “L” Length of the bore
- Alternative: the O.D., I.D., and Length of the existing parts
If we have those 3 dimensions for each part plus the quantity of each part required, we can provide a quote
Dimensions of Design
Figure 1: Dimensions for designing a Vespel® CR-6100 part
To design parts for fabrication, we will need the dimensions of the mating hardware. While many wear parts have a simple O.D., I.D., and Length profile, some parts have additional features for which we will want the dimensions:
- Some pump wear rings have profiles like an “L”, “T”, or “Z”. In those situations, we need to know each of the diameters and widths of any of the “shoulders” or “ribs” of the parts
- Is the pump axially or radially split?
- Are any of the parts are axially split?
- For vertical pump shaft bearings, it will be helpful to know if there is any groove profile required-spiral grooves, axial grooves, how many, what diameter, how deep…
- What is the existing material and clearance of the vertical pump shaft bearings?
Process Conditions
Vespel® CR-6100 works in most process services. It is manufactured from Teflon™ PFA and carbon fibers, so it is chemically resistant to nearly all process chemicals and it has a broad temperature range. There are only two general limitations:
- Temperature range is cryogenic -300 F (-200 C) to 500 F (260 C)
- Avoid abrasive slurries, slops, and bottoms services
To design the parts, the pump operating temperature is required in order to determine the correct press fit for the Vespel® CR-6100 parts.
Differential Pressure
If the components are going into a high-energy pump, such as a multi-stage horizontal charge pump or boiler feed water pump, we recommend that the patent-pending Boulden PERF-Seal™ design be used on all horizontal multi-stage pumps. The PERF-Seal™ design is fabricated from Vespel® CR-6100 and increases the efficiency gain and rotor damping associated with the upgrade. If the PERF-Seal™ is not used, we will need to know the differential pressure across the components in order to verify that they are designed correctly.
Figure 2: PERF-Seal center bushing from a boiler feed water pump
Conclusions
In the ideal situation, you can supply the dimensions of the parts required, the pump cross-sectional drawing, and the API data sheet for the pump. From this information, we can confirm that the service is a good fit for Vespel® CR-6100, quote the material or machined parts required, and make a recommendation on how to install Vespel® CR-6100 into the pump.
Please feel free to contact Boulden with your application details and dimensions. We’ll be happy to provide a budget estimate or a fixed quote depending on the information available. Once you decide to go forward with the upgrade, we have whatever material you need in stock in the USA, Europe, and Singapore.