The screw flow meter housing body forms the metered chamber around the screw spindles in screw pumps and positive displacement screw flow meters. Bore roundness, spindle centre distance and surface finish directly control volumetric efficiency and meter accuracy, so any casting variation shows up immediately as calibration drift. Ningbo Ruican investment casts the housing in stainless steel or bronze and machines the spindle bores, port faces and mounting flanges in-house to hold the geometry, giving OEMs a stable, repeatable metering body that calibrates on the first pass.
Specifications
| Casting process | Silica sol investment casting, near-net-shape bore coring |
|---|---|
| Material options | CF8M / 316 stainless, CF3M / 316L, aluminium bronze C95800, tin bronze, duplex 2205 |
| Dimensional tolerance (ISO 8062-3 CT grade) | CT6 as cast, CT5 on spindle bores and port faces after machining |
| Machining | In-house CNC boring, milling and tapping, spindle bores finish machined in one setup |
| Surface finish (Ra) | Ra 1.6 um as machined, Ra 0.8 um in the metering chamber |
| Pressure testing | Hydrostatic test at 1.5x design pressure, low pressure air decay test available |
| Weight range | 3.5 kg to 42 kg |
| Typical lead time | 6-8 weeks including tooling, 4-5 weeks for repeat orders |
Scope and options
Key features
- Cored spindle bores cast close to size, reducing machining allowance and cycle time.
- Spindle centre distance and parallelism machined in one setup for metered accuracy.
- Aluminium bronze option for seawater and low lubricity fluids with excellent wear behaviour.
- Homogeneous cast structure free of the weld distortion found in fabricated meter bodies.
- Port faces and flange sealing surfaces machined to the specified gasket finish.
- Pressure tested before and after machining to confirm the casting integrity.
Applications
- Three-screw and twin-screw positive displacement flow meters
- Fuel oil and lube oil transfer and metering skids
- Moreover, Custody transfer metering packages for marine bunkering
- Hydraulic power unit screw pump assemblies
- Chemical dosing and polymer feed screw pump systems
- Generally, Machine tool coolant and cutting oil supply pumps
Quality & compliance
Ningbo Ruican supplies every screw flow meter housing body with EN 10204 3.1 material certification showing chemical analysis, mechanical properties and heat identity. Bodies are hydrostatically tested to 1.5 times design pressure, and liquid penetrant, ultrasonic or radiographic NDT can be specified where the end user requires it. We provide a full dimensional report including bore diameter, centre distance and surface finish readings for the first article and for each production batch. PPAP and FAI documentation are prepared on request under our IATF 16949 certified system, and calibration support samples can be shipped ahead of serial release.
FAQ
Can you hold the bore tolerances needed for metering accuracy?
Yes. We core the bores in the casting and finish machine them in a single setup on CNC boring equipment, which holds centre distance and parallelism consistently. CT6 as cast and CT5 on machined features is our standard, and tighter limits can be agreed where the drawing demands them.
Which material is best for seawater service?
Still, aluminium bronze C95800 is the usual choice for seawater and brackish duty thanks to its erosion and biofouling resistance. Generally, duplex 2205 is an alternative where higher pressure ratings or lower weight are needed. In general, both are regularly cast and machined in our shop.
Do you supply fully machined and tested housings?
Additionally, most customers take fully machined, pressure tested and documented housings ready for assembly. We can also ship as-cast or rough machined bodies if you prefer to finish the metering chamber in your own facility under your calibration control.
How do you control dimensional drift across a production run?
We qualify the tooling and fixtures with a first article inspection, then run in-process checks on the critical bore and port features at defined intervals. Full CMM dimensional reports accompany every lot, so any drift is caught before parts are packed rather than at your assembly line.
Can you support a prototype before committing to tooling?
We can produce prototype housings using 3D printed patterns or a soft tool so you can validate fit, calibration and flow performance before production tooling is cut. In general, cost of the prototype route is credited against the production tooling on release of the program.
CTA
Send your screw flow meter housing drawing, material specification and expected annual volume for a fast quotation. Additionally, Ningbo Ruican will confirm the casting and machining route, lead time and sample plan for your OEM program. Contact window: Wendy She — sales@cnsandcasting.com — WhatsApp +86-13777124360. In addition, full factory information is on cnsandcasting.com.
