Altecnic / Caleffi 309 Series Pressure & Temperature Relief Valve 1/2" 90°C 10 Bar - 309400CST
The Altecnic / Caleffi 309 Pressure & Temperature Relief Valve - 309400CST is designed to effectively control and limit the temperature and pressure of hot water in domestic storage heaters. This essential safety valve ensures that water temperatures do not exceed 100°C, preventing steam formation. When the temperature or pressure reaches its set limits, the valve releases a sufficient amount of water into the atmosphere, ensuring that both temperature and pressure return to safe operating levels.
**How It Works:**
The valve features a thermostat compound within the temperature sensor that is submerged in the hot water storage heater. As the temperature increases, the compound expands, moving a thrust pin that activates the obturator, thereby opening the valve. This mechanism is set to initiate opening at temperatures exceeding 90°C. Regarding pressure, the obturator, which is countered by a spring, lifts when the pressure reaches its designated limit, fully opening the outlet. The pressure setting is predetermined based on the system's maximum permissible pressure. As the temperature and pressure decrease, the valve automatically re-closes within the specified tolerances.
**Product Specifications:**
- Size: 1/2"
- Connections: Male x Ø 15 mm with compression fitting for copper pipe
- Materials: DZR
- Medium: Water
- Set Pressure: 10 Barg
- Discharge Rating: 10 kW
- Temperature Setting: 90°C
- Probe Length: 102mm
- Product Code: 309400CST
**Notes:** WRAS approved, CE marked
This high-quality pressure and temperature relief valve is an indispensable component for maintaining the safety and efficiency of your domestic hot water system. Ensure optimal performance and compliance with regulations by choosing the Altecnic / Caleffi 309 Pressure & Temperature Relief Valve.
Other Products and Services from Flowstar (UK) Ltd
Altecnic / Caleffi 312 Series Safety Relief Valve 1/2" x 1/2" M x F 6 Bar - 312460CST
FSHRFDH - Rupture Disc Holder for Reverse Acting Discs
The FSHRFDH Rupture Disc Holder for Reverse Acting Discs is engineered to provide exceptional reliability for rupture discs. This holder is designed for direct installation onto piping systems and comprises two flanged components, complete with robust steel bolts. Fully customisable, it can be supplied with various coupling types, compatible as either female or male threaded NPT, Gas, or adhering to other international standards such as butt welding and socket welding.
Specifications
Compatible Discs: FSSCR, FSY90, FSKRD
Sizes: 3/4" (DN20) to 4" (DN100)
Materials: Carbon steel, Stainless steel (316L), Alloy 201, Alloy 400, Alloy 600, Alloy C276, Titanium, Tantalum
Linings: Available (PTFE or glass fibre reinforced PTFE)
Accessories: Nipples, T connectors, excess flow valve, pressure gauge.
To request a rupture disc holder, please download our Rupture Disc Request Form, complete it, and send it to sales@flowstar.co.uk.
FSSCDF - Forward Acting Rupture Discs
The FSSCDF Forward Acting Rupture Discs feature precision micro-scored sections that open in controlled petals, using four, six, or more radial score lines to ensure a clean, reliable opening while minimising the risk of petal separation. This design makes them particularly well suited for high burst pressure applications and for systems operating under cycling or pulsating conditions with gases or liquids, without compromising safety margins.
These discs respond to overpressure within milliseconds, opening fully without fragmentation, and are ideal for protecting safety relief valves. They support an operating-to-burst pressure ratio of up to 85%, offer excellent corrosion resistance, and can be further enhanced with an optional PTFE lining. In many applications, the discs can also withstand full vacuum conditions without additional supports, providing flexible installation options.
Key Specifications:
Sizes: 1" (DN25) to 36" (DN900)
Materials: Stainless steel, Alloy 201, 400, 600, 625, C276, Titanium
Burst Pressure Range: 2–413 bar g (30–6000 psi g), depending on size and material
Krl: 1.33
Tolerance: ±5% to ±20%
Operating Margin: Up to 85%
Temperature Range: –196°C to 600°C
Fragmentation: None – clean, petal opening
Use Under Valve: Yes
Corrosion Resistance: Very good
Linings: Optional
Holders: FSHI/A, FSHI/P, FSHI/F, FSHTC
Rupture Detection: Electrical, Magnetic, Inductive, Optical
Certifications: ASME (UD Stamp), PED (CE), ATEX EX II 2 GD
Flowstar (UK) Ltd
Wiltshire Road, Kingston-upon-Hull, East Riding of Yorkshire, HU4 6PA, United Kingdom
Flowstar (UK) Ltd is a leading global supplier of safety, relief, and reducing valves. With strong partnerships across major manufacturers, we deliver precise, reliable valve solutions tailored to your needs. Email enquiries to sales@flowstar.co.uk or call us on +44 (0)1482 601030.