YDK Rising Stem Supervisory Gate Valve | Model KRX-16S

According to TCVN 3890 and QCVN 06, central fire protection pump assemblies are required to be equipped with electrically supervised signal gate valves. Unlike conventional gate valves, the YDK rising stem signal gate valve, Model KRX-16S, is integrated with an OS&Y Switch for valve position monitoring. This switch assembly transmits the OPEN/CLOSED status of the valve to the central fire alarm panel (Alarm Panel). If someone accidentally or intentionally closes the valve that supplies firefighting water, the operator or technician can detect it immediately.

Construction of YDK KRX-16S Rising Stem Signal Gate Valve

Basically, the construction of this product is similar to the YDK rising stem gate valve. The only difference is that this gate valve is additionally equipped with a limit switch assembly mounted directly on the valve bonnet:

• OS&Y Monitoring Switch: Equipped with standard dry contacts (NO/NC), allowing flexible connection to most fire alarm and fault monitoring systems currently in use. When the valve is fully OPEN, the contact remains in its normal status. If someone turns the handwheel to partially close the valve by just a few turns, the sensor is immediately activated and sends a “Supervisory Signal” to the fire protection control panel.
• Epoxy-Coated GGG50 Ductile Iron Body: The valve body and bonnet are cast from ductile iron with excellent resistance to hydraulic impact. The surfaces are electrostatically coated with epoxy to prevent corrosion in humid pump room environments.
• EPDM Rubber-Coated Cast Gate: The ductile iron gate core is fully coated with elastic EPDM rubber, ensuring Class A shut-off performance (ISO 5208). Thanks to the elasticity of the rubber, the gate securely accommodates iron particles and fine sand inside the fire protection pipeline without scratching or causing leakage.
• SS420 Stainless Steel Stem: The valve stem is made of stainless steel with high torsional strength. With the threaded section exposed, visual inspection and periodic lubrication maintenance are extremely convenient.

YDK Rising Stem Signal Gate Valve Dimensions

Dimension table

Operating Principle of YDK Rising Stem Signal Gate Valve

The operating mechanism of the YDK rising stem signal gate valve combines mechanical transmission with an electrical contact switch:

Fully Open Position

When the handwheel is turned to open the valve, the stainless steel threaded stem rises out of the valve body, lifting the gate with it. At the highest position, the shoulder on the valve stem presses the actuator of the limit switch, keeping the electrical contact in a safe monitoring state (Normal Status). At this point, the central control panel recognizes that the pipeline is fully open and unobstructed.

Partially Closed or Fully Closed Position (Fault or Maintenance)

When the handwheel is turned in the opposite direction to close the valve, the threaded stem begins to move downward. As soon as the stem leaves the fully OPEN position (after only a few turns of the handwheel), the stem shoulder releases the limit switch actuator, changing the contact state (from NO to NC or vice versa). This change in the electrical circuit immediately sends a fault warning signal (Supervisory Signal) to the central control panel, together with the exact valve location, notifying the technician that the water pipeline has been interrupted.

Recommended Installation Locations for YDK Rising Stem Signal Gate Valve

In MEP design, the YDK KRX-16S signal gate valve is typically recommended for installation at critical locations:

• Suction / Discharge Pipelines of Fire Pump Assemblies: Ensures that the valve remains in the open position and ready to supply water when the fire pump is automatically activated.
• Inlet of Alarm Valve / Deluge Valve Assemblies: Monitors the main water supply line for automatic sprinkler fire protection systems by floor or fire compartment.
• Shut-Off Valve on Wall-Mounted Firefighting Water Supply Pipelines: Prevents operators from accidentally closing branch valves during building maintenance.

Supplier of Genuine YDK Rising Stem Signal Gate Valves in Vietnam

An Phu Thanh is a direct distributor of YDK rising stem signal gate valves for MEP, fire protection, and water supply and drainage infrastructure contractors nationwide. We ensure timely material supply according to project schedules and provide complete documentation required for project inspection and acceptance.

• Streamlined Fire Protection Inspection & Acceptance Procedures: All YDK valves distributed by us meet technical standards and are supplied with complete legal import documentation for submission during fire protection inspection and approval procedures.
• Optimized Investment Costs & Project Budgets: Thanks to direct importation without intermediaries, An Phu Thanh offers competitive market pricing and attractive discounts for construction projects, dealers, and other customers. This enables contractors to optimize MEP cost estimates and effectively control incoming material costs while maintaining the required quality and technical standards of the project.
• In-Stock & Fast Delivery: An Phu Thanh’s warehouse system maintains available stock of electrically supervised signal gate valves from DN50 to DN300, ready to fulfill urgent orders or additional quantities arising beyond the contractor’s original estimates.

If you need consultation or a quotation for the YDK KRX-16S rising stem signal gate valve, please contact An Phu Thanh via Hotline / Zalo: 0946 729 913. Our consulting team will respond promptly and provide dedicated support.