Besa 131 Safety Valve

**Altecnic / Caleffi 309 Pressure & Temperature Relief Valve (309500CST)** The Altecnic / Caleffi 309 Pressure & Temperature Relief Valve (model 309500CST) is expertly designed to monitor and regulate the temperature and pressure within domestic storage heaters. This valve plays a crucial role in preventing the water temperature from exceeding 100°C and averting the dangerous formation of steam. Once the specified limits are reached, the valve automatically discharges an adequate quantity of water, ensuring that both temperature and pressure are safely maintained within the system's operational parameters. **Operational Mechanism:** 1. **Temperature Regulation:** The valve's thermostat compound, housed within the temperature sensor submerged in the hot water storage heater, expands with a rise in temperature. This expansion causes a thrust pin to move, which in turn activates the obturator, resulting in the opening of the valve. The valve is calibrated to open when temperatures exceed 90°C. 2. **Pressure Regulation:** The obturator is countered by a predetermined spring. Upon reaching the designated pressure setting, the obturator elevates, fully opening the outlet. The pressure setting is based on the maximum allowable pressure for the system. As temperature and pressure lower, the valve automatically re-closes within the established tolerances. **Specifications:** - **Size:** 3/4" - **Connections:** Male x Ø 22 mm, featuring a compression fitting for copper piping - **Materials:** DZR (Dezincification Resistant) - **Medium:** Water - **Set Pressure:** 10 Barg - **Discharge Rating:** 25 kW - **Temperature Setting:** 90°C - **Probe Length:** 99 mm - **Product Code:** 309500CST - **Certifications:** WRAS approved, CE marked Ensure the safety and efficiency of your hot water system with the reliable Altecnic / Caleffi 309 Pressure & Temperature Relief Valve. Perfectly suited for domestic use, this valve meets strict industry standards while optimising your heating system's performance.

The Altecnic / Caleffi 253 Solar Safety Valve - 253046 is designed to regulate pressure within the primary circuits of solar heating systems. This valve is specifically chosen based on the required set pressure. As pressure increases within the system, the valve activates when the discharge pressure is reached, releasing excess pressure to the atmosphere. This vital function helps prevent potential damage to solar collectors and other system components caused by excessive pressure levels.

Specification

• Size: 1/2" x 3/4"
• Connections: BSP Female Inlet x BSP Female Outlet
• Materials: Brass (Chrome Plated)
• Medium: Water, Glycol Solutions (Maximum Glycol Percentage: 50%)
• Set Pressure: 6 Barg
• Temperature Range: -30 to +160 degrees Celsius
• Product Code: 253046
• Notes: CE marked

This reliable safety valve is an essential component for maintaining the efficiency and safety of your solar heating system. Its robust construction and advanced design ensure it meets industry standards, providing peace of mind for your installation.

Features & Benefits

• Delivers precise and accurate flow regulation
• User-friendly operation with a handwheel and clear numerical indicator
• Integrated orifice and test points – eliminating the need for separate DRV and metering stations
• WRAS Approved for use with drinking water up to 85°C
• Ensures consistent flow control across all handwheel settings
• The FODRV guarantees an accuracy of ± 5% across all settings, facilitating precise flow regulation and measurement

Specification

• Conforms to BS7350: 1990
• Handwheel operated for ease of use
• Includes a numerical indicator for clear readings
• Inside screw non-rising handwheel for compact design
• Features a characterised regulating disc
• Equipped with an integral fixed orifice
• Comes with two Figure 631 test points for enhanced functionality
• Flow charts available for reference
• End connections are threaded for secure attachment
• Available in sizes from 1 to 2" taper threaded
• Conforms to BS EN 10266 (ISO 7-1), formerly BS 21
• Available in sizes 1/2 & 3/4" to ISO 228 parallel
• Sizes DN15 & DN20 suitable for use with compression adaptors compatible with copper pipe to BS EN 1057 R250 (half hard)
• WRAS Approved Product for quality assurance

Pressure/Temperature Rating

• Please refer to the datasheet for detailed specifications.