Product Description
Extraction check valve is the use of imported technology, similar products in foreign countries, based on the use of the most advanced design, manufacturing, materials technology, re-developed to fully meet the domestic 600MW, 1000MW turbine steam extraction system below the valve products needed , The technical performance of the international advanced level, for nearly 100 power companies at home and abroad to provide hundreds of quality and cheap products, has won the praise of many users, has replaced some of the imports for the country to save a lot of foreign exchange. This series of products are mainly used in steam turbine steam extraction system below 600MW to prevent medium or water backflow and play a protective role in important facilities such as steam turbine pumps. Its performance requirements in the pipeline medium backflow, power outages, accidents and other abnormal state, the valve instantly shut down, the closure time of less than 0.5 seconds.

Features
1. Design and manufacturing acceptance criteria using ANSIB16.34, E101 or JB / T3595, strength and sealing performance in full compliance with standards;
2. The vacuum state of the valve vacuum test, the whole life to meet user requirements;
3. For different temperatures, the main material using carbon steel or high temperature steel, sealing surface surfacing cemented carbide;
4. The valve flap is designed to be connected with the valve rod through the rocker lever, self-aligning with the valve sealing cover to ensure the sealing surface is consistent;
5. The seat sealing surface tilted a certain angle, reducing the closing time, reduce the impact of protection of the equipment itself and pipeline safety;
6. The valve is equipped with damping heavy hammer, can balance the closing moment dynamic torque, to prevent the hammer does not occur;
7. The body cavity with streamlined design, flow capacity, reducing valve resistance;
8. The actuator is a spring reset cylinder or hydraulic cylinder, and the relative action of the valve closing member is relatively independent, the actuator failure does not affect the closing member action;
9. Cylinder or hydraulic cylinder wall coated with wear-resistant corrosion-resistant layer, can increase life expectancy, reduce the movement resistance, the valve flexible and reliable;
10. Closing pieces open with limit mechanism, to avoid opening over the place to cause damage;
11. The implementing agency with a valve switch position signal output, the valve open position on-site instructions;
12. Can also be targeted according to the specific requirements of users design.

Design and manufacture acceptance criteria
Design and manufacture of standards: ASME / ANSIB16.34, E101, JB / T3595
Structural length standards: JB / T3595, ASME / ANSIB16.10, GB / T12221
Welding end or flange standard: GB / T12224, ASME / ANSIB16.25, GB / T9113, JB / T79 ~ JB / T82
Test acceptance criteria: JB / T9092, JB / T3595, ASME / ANSIB16.34, E101

Use and performance specifications
H664Y valve is used in non-corrosive media such as power plant or thermal power plant exhaust system, or other systems and water to prevent sudden drop of pressure in the steam turbine during steam turbine load. The steam in the steam exhaust pipe and each heater flows back into the steam turbine Resulting in broken pieces of the steam turbine to destroy the turbogenerator accident and to prevent leakage of the heater piping system to close the water from the extraction of steam to ensure that the feed water heater appears high water level when the pneumatic device components connected to the liquid After the counter-current signal, the turbines are quickly isolated to maximize protection of the turbine or extraction system.