| Feature | Detail | |---------|--------| | Impeller | Closed, backward‑curved (BC) design; detachable, balanced, and reversible. Material: high‑strength cast iron (DIN 1699) or stainless steel (AISI 304/316). | | Volute | Split‑case volute with removable cover for easy inspection. Material matches impeller (cast iron or stainless). | | Shaft | Hardened steel, key‑less (splined) connection to motor hub; C3 tolerance class for high‑speed service. | | Bearings | Double‑row angular contact ball bearings, lubricated for life (sealed). Optional ceramic hybrid for high‑temperature service. | | Mechanical seal | Dual‑seal arrangement (single‑seal option available). Materials: carbon‑silicon carbide (C‑SiC) or ceramic‑ceramic; optional oil‑free seal for sanitary applications. | | Casing | Rigid, bolted split‑case (16‑bolt pattern). Standard pressure rating: PN 10 (≈ 1 bar) – can be ordered up to PN 16 with reinforced flange. | | Suction & discharge | DN 90 (3‑inch) up to DN 600 (24‑inch) flanges; ANSI‑B16.5 or EN‑1092‑1. Optional threaded or welded connections. | | Base & mounting | Rigid footplate with integrated vibration isolation pads (optional). Can be mounted on a skid, concrete pad, or directly on a machine frame. | | Drive coupling | Rigid (direct) coupling with key‑less spline hub; optional flexible coupling for misalignment compensation (up to 0.5 mm). | | Cooling | Pump body serves as the primary heat sink; optional external water jacket for high‑temperature fluids. |
| Item | Recommended Practice | |------|-----------------------| | Suction pipe | Minimum pipe length: 3 D (≈ 1 m for DN 300) straight pipe upstream of the pump; avoid elbows within this length. | | Net Positive Suction Head (NPSHA) | Verify NPSHA ≥ NPSHR + 0.5 m (safety margin). Use a pressure‑transducer or calculate based on fluid level, vapor pressure, and friction losses. | | Check valve | Install downstream of the pump only if the system requires back‑flow protection; otherwise, a non‑return valve adds unnecessary head loss. | | Strainer | Use a Y‑type strainer (mesh ≈ 2 mm) upstream; cleanable without dismantling the pump. | | Discharge | Provide at least 2 D of straight pipe downstream of the pump before the first valve or bend. |
| Item | Description |
|------|-------------|
| Product family | KSB J‑Series (single‑stage, end‑suction, close‑coupled centrifugal pumps) |
| Model | J‑291 |
| Design purpose | General‑purpose liquid handling for water, light oils, and non‑corrosive chemicals in HVAC, municipal, industrial and agricultural applications. |
| Typical ratings | 0.5 – 250 m³ h⁻¹ (≈ 130 – 66 000 gpm) at heads up to 90 m (≈ 300 ft). |
| Drive options | Direct‑coupled to a standard 3‑phase motor (up to 355 kW) or optional belt‑drive configuration. |
| Certifications | ISO 9001, ISO 14001, ATEX‑II 3G (explosion‑proof version), CE‑marked, ANSI/ASME B73.1 compliance. |
| Key selling points | • Compact, low‑profile design (≤ 1.2 m overall height)
• High‑efficiency hydraulic profile (up to 85 % at BEP)
• Easy access for maintenance (removable volute/impeller)
• Wide range of impeller‑diameter (D = 290 mm nominal)
• Robust cast‑iron or stainless‑steel (AISI 304/316) construction. | KSBJ-291
The J‑291 is the “work‑horse” of KSB’s J‑Series, often chosen when a reliable, low‑maintenance pump is needed in a relatively confined installation space. It is especially popular in:
| Component | Standard Material | Optional Materials | |-----------|-------------------|---------------------| | Casing & volute | Cast iron (DIN 1699) | Stainless steel AISI 304, 316 (corrosive media) | | Impeller | Cast iron (DIN 1699) | Stainless steel AISI 304/316, bronze (high‑temperature) | | Shaft | Hardened carbon steel (C45) | Duplex stainless (for aggressive environments) | | Mechanical seal | Carbon‑silicon carbide (C‑SiC) | Ceramic‑ceramic, PTFE‑graphite (food‑grade) | | Bearing housing | Cast iron | Stainless steel (for sanitary) | | Gasket | Spiral wound (graphite) | PTFE, metal‑to‑metal (high‑temperature) | | Feature | Detail | |---------|--------| | Impeller
Corrosion‑resistant versions (stainless) are recommended for:
| Flow (m³ h⁻¹) | Head (m) | Power (kW) | Efficiency (%) | |---------------|----------|------------|-----------------| | 0 (shut‑off) | 88 | 0 | – | | 50 | 78 | 9.5 | 71 | | 100 | 62 | 14.5 | 79 | | 150 | 45 | 17.2 | 81 | | 180 (BE) | 36 | 18.1 | 85 | | 210 | 26 | 18.8 | 79 | | 240 | 15 | 19.0 | 73 | | 260 (free‑delivery) | 5 | 18.5 | 68 | | Component | Standard Material | Optional Materials
*BE = Best‑Efficiency Point (≈ 180 m³ h⁻¹ for this size).
The NPSHR (net positive suction head required) at BE is 0.9 m (≈ 3 ft). This value is a strong indicator of the pump’s ability to operate on low‑suction systems without cavitation.
The J‑291 family is geometrically similar, allowing the use of the affinity laws to extrapolate performance for other sizes (DN 90‑600).
All curves are supplied in the KSB “Pump Performance Handbook – J‑Series” (Rev 3, 2024) and are available as an Excel spreadsheet for quick sizing.