Link to the catalogue • Items 2240 - 2250
🔗 PDF datasheet double intake “non-stick” valves
The items
Art. 2240 — Double intake non-stick valve with PN6/PN16 flanges and position indicator
Art. 2250 — Double intake non-stick valve with F-F-F threaded connections and position indicator
Applications
Items 2240 and 2250 are Guidi patented non-stick valves, developed in 2007.
Non-stick valves were developed to address a recurring problem on board: conventional valves tend to accumulate fouling, scale deposits and dirt internally, which over time makes them difficult to operate and can cause them to seize completely. Guidi non-stick valves are designed to reduce these risks and maintain long-term operability.
They are installed in engine rooms and serve the cooling circuits of main engines, generators, watermakers and air-conditioning systems. Items 2240 and 2250 are specifically designed for engine applications: the third connection allows emergency bilge-water suction using the engine cooling circuit itself, without installing an additional dedicated valve.
In addition to the name “double intake valve”, these items are commonly referred to in the field as three-way valves, or safety valves, the latter term used more generally for the entire Guidi non-stick valve range.
Comparable products are available on the market in both metal and plastic versions, with different technical characteristics and performance levels.
Material
The body of valves 2240 and 2250 is made of bronze. Bronze is the most suitable material for seawater systems due to its long-term resistance to marine corrosion.
To minimise galvanic corrosion risks, it is advisable for the entire installation to use compatible bronze components: water intake, valve, fittings and through-hull fittings. The use of mixed materials within the same circuit should be carefully evaluated.
Geometry and operating principle
The internal geometry of valves 2240 and 2250 is designed to minimise pressure losses, optimise water flow, limit air-bubble formation and reduce installation height.
These are full-flow valves: although the internal flow path is not straight, the internal geometry does not introduce significant restrictions to the flow. The double-intake configuration allows alternating selection of the water source — seawater or bilge water — depending on the operating position.
Cavitation
Cavitation is a physical phenomenon that occurs when local pressure variations within a fluid generate vapour-filled cavities. These manifest as bubbles which, upon imploding, produce microjets at very high pressure.
The effects of cavitation include noise, vibration, mechanical damage to metal surfaces through erosion, and loss of circuit efficiency. On metal surfaces, erosive pits — small localised cavities — may form.
The Guidi system — valve, water intake, fittings and strainers — is designed to reduce the conditions that promote cavitation.
Recommended system configuration
For optimum hydraulic performance, Guidi recommends combining valves 2240 and 2250 with:
- Guidi water intakes Art. 1112B and 1113B (patented)
- Guidi through-hull fitting Art. 1260 (patented)
- Water intake system Art. 1260 with cap Art. 1261 (patented) or Art. 1262 (patented)
- Guidi strainers suited to the installation (patented)
- A rubber-disc foot valve on the bilge suction line
The overall system is designed to reduce pressure losses, limit turbulence and contain cavitation phenomena.
Sizing
The choice of size depends on the hydraulic system characteristics, engine requirements and the number of circuits to be served. The choice between the flanged version (2240) and the threaded version (2250) depends on the installation configuration.
Pressure-loss data must be taken into account during system design. Valve oversizing is generally not required.
The designations PN6 and PN16 identify the flange drilling pattern and dimensional standard, not the valve operating pressure. The selection depends on the piping class of the installation, as defined during system design by the shipyard. Both versions are available.
Approvals and certifications
Items 2240 and 2250 hold RINA and Lloyd’s Register Type Approval.
The RINA Type Approval is based on standard ISO 9093:2020. The valves are approved for installation on vessels with a hull length up to 24 metres, as defined by ISO 8666. For vessels above 24 metres, the same valves may be used subject to specific testing carried out under RINA regulations, depending on installation position and valve size.
The Lloyd’s Register Type Approval is based on ISO 9093:2020 and Lloyd’s internal regulations. For vessels above 24 metres, specific testing is carried out under Lloyd’s regulations, depending on installation position and valve size.
Items 2240 and 2250 are patented items.
Inspections and testing
Material inspections are carried out before manufacturing. During production, valves undergo dimensional, assembly and packaging inspections.
At the end of production, air-pressure testing is always performed: the valve is pressurised to a defined level and checked for leakage. This method is fast, efficient and does not contaminate the parts. The document issued is an internal certificate, compliant with Guidi quality procedures, as this test is not supervised by external inspection bodies.
Hydrostatic testing is carried out using water emulsified with oil, pressurised for a defined period according to internal procedures. These tests are performed under supervision of external inspection bodies. Water emulsified with oil is used because it is recovered from machinery before disposal; its white colour facilitates leakage detection. When required, the document issued is a 3.2 inspection certificate according to UNI EN 10204:2005.
Usage
Valves 2240 and 2250 are installed in the main engine cooling circuit. The third connection must be linked to a pipe reaching the bilge, with appropriate fittings and a foot valve with filtering element.
During normal operation, the seawater intake is open: seawater enters the cooling circuit and is discharged through the engine exhaust in the normal way.
In emergency situations — hull leakage, flooding or excessive bilge water — the main seawater intake can be closed. Closing this intake simultaneously opens the bilge suction line. Bilge water enters the cooling circuit, is used to cool the engine and discharged overboard through the exhaust. This allows the vessel to continue navigating towards a safe port.
Installation
All valves are supplied with the seawater intake in the open position. Before installation, visually verify that the flow passage is unobstructed and that the handwheel indicator shows the position APERTO MARE / SEA OPEN.
The flow direction must correspond to the arrow marked on the valve body. Valves may be installed in either vertical or horizontal position. For the flanged version (2240), use the gaskets supplied. The handwheel must remain accessible to the operator.
For the main seawater system, valves are mounted directly on the hull water intake. They may also be used in water-distribution manifolds and internal utility systems.
The handwheel is fitted with a position indicator that allows quick identification of the valve operating configuration. Each valve is supplied with a dedicated installation and maintenance manual.
Maintenance
The valves require minimal maintenance. Annual cleaning and inspection is recommended, along with a functional test before the boating season and periodic checks during haul-out with the vessel out of the water.
The most common contaminants that may accumulate internally are fouling, plastic debris, branches and foreign objects. These materials can prevent full closure of the valve or damage the neoprene membrane.
After cleaning, inspect the neoprene membrane for cuts, wear or damage. If the membrane is damaged, the control kit must be replaced. If the kit is intact, replacing the gaskets alone may be sufficient.
Include the valves in the vessel’s cathodic protection and bonding system.
Spare parts
Only original Guidi spare parts are recommended, with reference to the item code. Spare parts are available at guidisrl.it and through direct purchase.
Double intake valve control kit (KIT2240) This is the internal opening and closing wedge assembly of valves 2240 and 2250. It is designed to be removed without dismantling the valve body, using a wrench, for maintenance, inspection and replacement purposes. Replacement can be carried out by experienced personnel with the vessel out of the water, following the instructions supplied with the valve; the intervention of a qualified technician is nonetheless recommended.
Neoprene gaskets The gasket is included in the control kit. Neoprene gaskets are the correct choice for resistance to salt water.
Screws and nuts Available separately. Guidi recommends A4 low-carbon austenitic stainless steel fasteners.
Durability
Valves 2240 and 2250 are designed to maintain their physical and mechanical characteristics over time with minimal routine maintenance. The modular construction facilitates maintenance, disassembly and material recovery. At end of life, most components can be recovered through dedicated raw-material recycling processes.