The port plate body sits between the impeller and the end cover of a liquid ring vacuum pump or compressor, carrying the suction and discharge ports that control the compression cycle. It runs in a wet, often corrosive gas stream at close axial clearance, so casting distortion, porosity or a rough port surface degrades vacuum level and capacity. Ningbo Ruican investment casts the port plate in stainless steel or bronze and machines the port windows, flat faces and pilot diameters in-house to hold flatness and clearance so the pump pulls design vacuum from start-up.
Specifications
| Casting process | Silica sol investment casting, stress relieved before machining |
|---|---|
| Material options | CF8M / 316 stainless, duplex 2205, aluminium bronze C95800, tin bronze |
| Dimensional tolerance (ISO 8062-3 CT grade) | CT6 as cast, CT5 on sealing faces and pilot diameters after machining |
| Machining | In-house CNC turning and milling of ports, faces and pilot diameters |
| Surface finish (Ra) | Ra 1.6 um as machined, Ra 0.8 um on sealing and port faces |
| Pressure testing | Hydrostatic test at 1.5x design pressure, NDT screening on request |
| Weight range | 2.6 kg to 38 kg |
| Typical lead time | 6-8 weeks including tooling, 4-5 weeks for repeat orders |
Scope and options
Key features
- Cast port windows produced close to final size, reducing milling time and tool wear.
- Stress relieved before finish machining so flatness is stable in service.
- Aluminium bronze and duplex options for corrosive or chlorinated gas streams.
- Port profile optimised with the casting simulation to keep flow losses low.
- Sealing faces machined flat to protect the axial clearance to the impeller.
- Interchangeable with OEM geometry, including non-standard port timing.
Applications
- Single stage and two stage liquid ring vacuum pumps
- Liquid ring compressors for chlorine and vinyl chloride service
- Power plant condenser vacuum and air removal packages
- Paper mill vacuum systems and dewatering suction rolls
- Chemical and pharmaceutical solvent recovery vacuum skids
- Flare gas and vapour recovery liquid ring compressor trains
Quality & compliance
Each port plate body ships with EN 10204 3.1 material certification covering chemical analysis and mechanical properties for the casting heat, plus heat treatment records where stress relief or solution annealing applies. Hydrostatic testing at 1.5 times design pressure is standard, and dye penetrant, ultrasonic or radiographic NDT screening can be specified for critical vacuum and compressor duty. Moreover, dimensional reports document sealing face flatness, port geometry and pilot diameters for first article and production lots. Ningbo Ruican prepares PPAP and FAI packages on request under our IATF 16949 certified quality system, and we retain inspection records for the duration of the program.
FAQ
Why choose bronze for a liquid ring vacuum pump port plate?
Bronze and aluminium bronze resist the wet, often chlorinated gas streams found in chemical vacuum duty and give excellent bearing behaviour if the impeller rubs. Generally, duplex 2205 is preferred where higher strength or higher pressure ratings are needed. In general, we cast and machine both routinely.
How do you keep the plate flat after machining?
We stress relieve the casting before finish machining, then rough and finish machine the sealing faces with balanced stock removal. Flatness is verified on the CMM or on a surface plate and recorded in the dimensional report, so any movement is detected before the part leaves our shop.
Can you reproduce an existing port plate from a sample?
Yes. Provide a sample or 3D scan data and we will confirm the port timing and geometry against your pump performance requirements before cutting tooling. Additionally, alternatively, we build directly to your drawing with no reverse engineering needed.
What testing do you perform as standard?
Hydrostatic testing at 1.5 times design pressure is standard on every pressure-retaining body. Liquid penetrant inspection of machined faces, helium leak testing and radiographic screening are available on request, and we test to your written procedure where one is supplied.
Do you supply spare port plates for older pump models?
We regularly support aftermarket and service programs for older liquid ring machines, including sizes no longer stocked by the original manufacturer. Send the drawing or sample and we will confirm material equivalence, lead time and a practical minimum release quantity.
CTA
Send your liquid ring vacuum pump port plate drawing, material requirement and annual volume and Ningbo Ruican will return a quotation and process proposal within 48 hours. We support vacuum and compressor OEMs as well as service companies with aftermarket replacements. Contact window: Wendy She — sales@cnsandcasting.com — WhatsApp +86-13777124360. In general, visit cnsandcasting.com to review our vacuum pump component range.
