SPIRAX SARCO · CONTROL VALVES
Spirax Sarco QLM & QLD Series Three-Port Control Valves – Mixing & Diverting Service
Spirax Sarco QLM/QLD three-port control valves for mixing & diverting. Cast iron, carbon steel, stainless steel. DN15-DN200. Buy from PC Engineering India.
Overview
The Spirax Sarco QLM and QLD Series are three-port control valves engineered for mixing and diverting service in industrial process systems. The QLM variants are designed for mixing applications, while the QLD variants handle diverting duties. Both feature a linear characteristic "V" port plug design, ensuring accurate and repeatable flow control across a 30:1 rangeability.
These valves are suitable for a wide range of media including thermal oil, compressed air, steam, condensate, and other compatible fluids. Available in four body materials—cast iron, SG iron, carbon steel, and stainless steel—the QLM/QLD series can be configured to meet diverse process requirements and corrosion resistance needs.
Standard stem sealing utilises spring-adjusted PTFE chevrons, with options for high-temperature graphite seals or metal bellows with supplementary safety packing. Seat options include metal-to-metal (EN 60534-4 Class IV), stellite-faced for enhanced wear resistance, or PTFE soft seats for tight shut-off (EN 60534-4 Class VI). The valves are compatible with Spirax Sarco pneumatic (PN9000E, PN9000R) and electric (AEL3, AEL7, AEL8) actuators.
Key Features
- Three-port design for mixing (QLM) or diverting (QLD) service
- Linear characteristic "V" port plug for precise modulating control
- 30:1 rangeability for broad operational flexibility
- Multiple body materials: cast iron, SG iron, carbon steel, stainless steel
- Seat options: metal-to-metal, stellite-faced, or PTFE soft seal
- Stem sealing: PTFE chevrons (standard), graphite, or metal bellows
- Flanged connections to EN 1092; JIS and ASME flanges available on request
- Compatible with Spirax Sarco pneumatic and electric actuators
Specifications
| Parameter | Value | ||
|---|---|---|---|
| Valve Types | QLM (Mixing), QLD (Diverting) | ||
| Size Range | DN15 to DN200 | ||
| Body Materials | Cast Iron (QL33), Carbon Steel (QL43), Stainless Steel (QL63), SG Iron (QL73) | ||
| Pressure Class | PN16, PN25, PN40 (varies by material) | ||
| Temperature Range | –29°C to +400°C (depends on body/bonnet configuration) | ||
| Plug Characteristic | Linear | ||
| Plug Design | "V" Port | ||
| Leakage Class | EN 60534-4 Class IV (metal seats), Class VI (PTFE soft seal) | ||
| Rangeability | 30:1 | ||
| Travel | 20 mm (DN15–DN50), 30 mm (DN65–DN100), 50 mm (DN125–DN200) | ||
| Flange Standard | EN 1092 (JIS/ASME on request) | ||
| Stem Sealing | PTFE chevrons (standard), graphite, metal bellows | ||
| Model | Material | Max Pressure (bar) | Temperature Range (°C) |
| QL33M/QL33D | Cast Iron | 16 | –5 to +200 |
| QL73M/QL73D | SG Iron | 25 | –10 to +300 |
| QL43M/QL43D | Carbon Steel | 40 | –29 to +400 |
| QL63M/QL63D | Stainless Steel | 40 | –29 to +400 |
Applications
- HVAC heating and cooling systems (mixing/diverting hot and chilled water) - Steam and condensate temperature control - Thermal oil circuits in process industries - Compressed air blending and distribution - Chemical and pharmaceutical process control - Food and beverage processing plants - Textile and paper manufacturing
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