Q: What is the basic information I need to provide to a shaft seal manufacturer to receive a quote?
Designing a mechanical shaft seal to meet the specific needs of your equipment and process parameters requires sharing information. To ensure the best design and seal performance, open dialogue between you (the customer) and the seal manufacturer starts with the first inquiry.
To start the discussion and allow a chance for a rapid proposal, providing available specifications or your best estimates to the items listed under Phase 1 is sufficient. If the supplier indicates the shaft seal is feasible and you're still interested after the supplier's response to the Phase 1 specifications, expanding the specifications found under Phase 2 and Phase 3 below confirms and refines the results from Phase 1.
Phase 1: Understanding the basics for the initial feasibility and proposal stage.
Provide your supplier with the following information:
- Shaft diameter
- Shaft rpm
- Shaft position: horizontal, vertical, or inclined
- Pressure ranges
- Temperature ranges
- Duty cycle
- Explosive concerns (yes/no)
- Process material: dry powders, pastes, slurries, liquids, and vapors, or all that apply
- Any known or specified materials of construction available to consider or eliminate. (If this information isn't readily available, we start with typical materials for the outlined parameters.)
Phase 2: Understanding the physical space available. Checking fit, sizing, and serviceability of the seal.
Provide your supplier with the following additional details:
- Axial space open along the shaft from the mounting surface to the bearing, coupling or axial obstructions. Include any steps in shaft diameters or sleeve protrusions, too.
- Radial clearance around the shaft. If obstructed at one or two positions, specify how far away and how much open space is available.
- Mounting bolt pattern (bolt or stud type), quantity, size, and position on a clock face.
- Detail whether this is a new build or existing equipment.
Phase 3: Expand on the operational parameters, equipment assembly, and the application history.
Provide your supplier with the following details to help complete the quote process:
- Expanded details on the first two phases to refine and define the specifics of the duty cycle, operating conditions, and possible cleaning methods or service cycles.
- Equipment history
- Process history
- Past sealing approaches
- Materials of construction review
- Purge and quench controls and approaches
- Explosion protections or ATEX review
- Other pertinent details specific to the application
Providing application information for a mechanical seal may seem overwhelming at first but breaking the process down into phases simplifies the task. Sharing the knowns or best estimates begins the process and determines if the other phases merit action or you may uncover a standard mechanical seal meets the needs. As the three phases are completed and details are expanded, clarity emerges. This will allow you to choose the correct shaft seal for your requirements.
Custom mechanical seal designs are sometimes needed for process equipment other than pump seals. Most process equipment conforms to limited sizing standards and uses of the equipment vary over a wide spectrum of industries. These factors further the need for a custom-designed solution versus using a standard pump or top-entry mixer seal.