Field Notes on a Workhorse: The SSH Single-Stage Double-Suction Split Case Pump

If you’ve spent any time around municipal waterworks or big HVAC plants, you already know the quiet backbone is often a Horizontal Split Case Pump. The SSH S/SH series from Shifo Town, Anguo City, Hebei has been making the rounds lately—partly because it hits the classic efficiency-versus-maintainability sweet spot, and partly because (to be honest) it’s priced sensibly without looking cheap.

What’s Trending in Split-Case Land

Across the industry, I’m seeing three things: higher-efficiency hydraulics (think redesigned double-suction impellers), VFD-ready setups to trim energy peaks, and better coatings for raw water. Many customers say they want “install and forget,” but they also want 1–2% more wire-to-water efficiency. The SSH series leans into that reality with modern, energy-saving hydraulics—without getting fussy to service.

Core Specs (real-world use may vary)

Test snapshot from a recent factory run: Q=2,600 m³/h at H=68 m; η=86.5% (ISO 9906 Grade 2B), NPSHr ≈ 4.1 m; vibration 3.8 mm/s RMS (ISO 10816-3 guideline). Acceptable, with a little room to optimize on the VFD curve.

Why a Horizontal Split Case Pump Still Wins

• Split casing = fast top-lift maintenance; no pipe disturbance.
• Double-suction impeller balances axial thrust; bearings live longer (often 40,000–60,000 h).
• Low NPSHr and gentle suction velocities—good for raw water and cooling duty.
• Stable curve, easy to trim to BEP. Operators love predictability.

Applications I See Most

Municipal water transfer, district cooling/HVAC, irrigation, light industrial process water, desalination intake/transfer, and (when configured per NFPA 20) fire protection. One plant manager told me, “It just runs—our team isn’t chasing seals every quarter,” which is exactly the point.

Manufacturing and QA Flow (short version)

Materials are selected per duty: ductile iron casings for pressure, 316 impellers for chlorides. Castings are normalized, machined on CNC, impellers balanced to ISO 1940-1 G6.3 (some to G2.5 on request). Hydrostatic test ≈ 1.5× rated pressure; performance test to ISO 9906 (Grade 2B or 1B by PO). Coatings per ISO 12944 (C3–C4). Documentation pack can include MTRs, FAT reports, and vibration plots.

Vendor Comparison (indicative)

Customization Notes

Options include trims for BEP targeting, duplex SS for seawater, hard-face seals (SiC/SiC), bearing RTDs and vibration sensors, and VFD-ready motors (IE3–IE4, sometimes IE5 with PM). Flanges per ISO 7005 or ASME B16.5.

Two Quick Case Notes

Hebei municipal transfer: three duty/standby Horizontal Split Case Pump units, each ≈ 3,000 m³/h @ 75 m. Energy use cut ≈ 9% after impeller trim and VFD commissioning.

District cooling (GCC): chilled water primary pumps, 316 wetted parts. Vibration measured 2.9 mm/s RMS at BEP—comfortably within spec, with low NPSHr margin observed during summer peaks.

What Buyers Keep Asking

“Will it last?” With proper alignment, clean suction, and quarterly checks, these run for years. Bearings usually outlast seals; plan a seal kit at 18–24 months for continuous duty, sooner on dirty water. Certifications available include ISO 9001, CE marking, and ISO 9906 performance reports on request.

References

1. ISO 9906: Rotodynamic pumps — Hydraulic performance acceptance tests.
2. API 610: Centrifugal Pumps for Petroleum, Petrochemical and Natural Gas Industries.
3. ISO 1940-1: Mechanical vibration — Balance quality requirements for rotors.
4. ISO 10816-3: Mechanical vibration — Evaluation of machine vibration by measurements on non-rotating parts.
5. ISO 12944: Paints and varnishes — Corrosion protection of steel structures by protective paint systems.
6. NFPA 20: Standard for the Installation of Stationary Pumps for Fire Protection.