Overview
A three-way diverter valve body routes flow from one inlet to either of two outlets, or merges two streams into one, using a rotating plug, ball or diverter disc. The casting is challenging because three intersecting flow paths create heavy junctions where shrinkage and hot tearing concentrate, and because the internal port geometry must be smooth enough to avoid product hold-up. Ningbo Ruican addresses this with solidification simulation on every new body, followed by silica-sol investment casting for the smooth internal surface finish that sanitary and food-grade service demands, or resin sand casting for larger carbon and low-temperature steel sizes, and full CNC machining of the ports and end connections.
Specification
| Parameter | Capability |
|---|---|
| Materials | CF8M / AISI 316, CF8 / 304, CF3M / 316L, duplex 2205, WCB carbon steel, LCB/LCC low-temperature carbon steel, ductile iron QT450-10 |
| Process | Silica-sol or water-glass investment casting; resin sand casting + CNC for large-bore bodies |
| Dimensional tolerance | ISO 8062 CT5–CT7; port bores and end connections to CT4–CT5 after machining |
| Size range | DN15–DN250 investment cast; DN250–DN500 resin sand cast |
| Pressure rating | Supplied to customer specification for ASME Class 150 / 300 / 600 and PN10–PN40 designs |
| NDT | RT per ASTM E94 / E446 on port junctions, UT per ASTM A609, MT per ASTM E709, PT per ASTM E165 |
| Testing | Hydrostatic shell test, seat-leakage test across both outlet paths, flow path verification |
| Heat treatment | Solution annealing for stainless and duplex; normalising or quench & temper for WCB and LCB/LCC |
| Surface finish | Internal flow paths to Ra 0.8 µm on electropolished CF3M; Ra 1.6–3.2 µm standard machined; external glass bead or pickle and passivate |
| Documentation | EN 10204 3.1 or 3.2, FAI and PPAP, PMI report, heat-to-part and surface finish traceability |
Key features
- Solidification simulation on every new body to eliminate shrinkage at the three-port junction.
- Smooth as-cast internal flow paths, with electropolishing to Ra 0.8 µm available for sanitary duty.
- End connections machined to tri-clamp, DIN 11851, flanged or threaded specification on the same body.
- Port-to-port dimensional control within 0.05 mm so the plug or disc seals on both seats.
- Low dead-leg geometry available for CIP and SIP cleaning in food and pharmaceutical service.
- Full penetration RT coverage of the junction area, with film or digital records retained by heat number.
Applications
- Food, beverage and dairy product routing and CIP return lines
- Pharmaceutical and bioprocess transfer and sampling systems
- Chemical plant blending, dosing and bypass arrangements
- Water treatment filter backwash and distribution manifolds
- Pneumatic conveying and bulk solids diverter duties in larger sizes
Quality & compliance
Diverter valve bodies are produced under an IATF 16949-certified quality system with melt control, simulated solidification, and NDT focused on the port junction where defects concentrate. Material is released to EN 10204 3.1, or EN 10204 3.2 with third-party witness when specified. PMI confirms alloy grade on every stainless and duplex heat, and surface finish is verified with calibrated roughness measurement on the flow path. Hydrostatic shell testing and seat-leakage testing across both outlet paths are performed to the purchaser’s procedure. FAI and PPAP Level 3 documentation with capability data on port geometry supports series release. Components are supplied to customer specification with full traceability; we do not hold or claim an API monogram licence or a PED notified-body licence.
FAQ
Why is the three-port junction the difficult part of this casting?
Three intersecting flow paths create a mass concentration that solidifies last, so shrinkage porosity and hot tears form there if the feeder design is wrong. We simulate every new body, adjust feeder and chill placement from the result, and verify the junction with radiographic testing on first articles.
Can you supply a sanitary finish for food and pharmaceutical use?
Yes. CF3M / 316L bodies can be electropolished to Ra 0.8 µm or better on the internal flow path, with external glass bead or pickled and passivated finish. Surface roughness is measured and reported in the FAI package.
Which end connections can you machine?
Tri-clamp, DIN 11851 dairy union, SMS, RJT, ISO and ASME flanges, BSP and NPT threads, and butt-weld ends. Different connections can be combined on the same body if your process layout requires it.
Do you supply the plug, disc or ball as well?
We can. Ningbo Ruican machines matched plugs, balls and discs from bar or casting, lapped and fitted to the body. Many customers prefer to fit their own trim, so we are happy to supply body-only.
How do you test seat leakage on a diverter body?
We hydrostatically test the shell and then seat test each outlet path separately against the closed plug or disc, recording leakage against the acceptance level your drawing specifies. Charts are serialised and filed with the job pack.
What is the difference between a diverter and a mixing three-way body?
A diverter takes one inlet to either of two outlets. A mixer takes two inlets to one common outlet. The castings look similar but the internal port angles and the plug geometry differ, and the pressure drops across the paths are not symmetrical. Please state which function you need.
