Key Components

1. Body Material: Ductile Iron
   • Description: The valve body is made from ductile iron, a material that offers higher tensile strength, impact resistance, and flexibility compared to traditional cast iron.
   • Benefits:
     • Superior resistance to mechanical stress and shock.
     • Higher pressure and temperature resistance than gray cast iron.
     • Better resistance to corrosion when coated (e.g., with epoxy coating) for use in water systems.
2. Gate (Disc)
   • Description: The gate, often made of ductile iron, is fully encapsulated in a resilient material (commonly EPDM rubber) to provide a bubble-tight seal.
   • Benefits:
     • The resilient material allows for a tight, leak-proof seal.
     • Reduces wear and tear on the sealing surfaces, increasing durability and lifespan.
3. Non-Rising Stem (NRS)
   • Description: Unlike rising stem valves, the stem remains stationary as the gate moves up and down.
   • Benefits:
     • Space-saving design: Ideal for installations in confined spaces or underground systems where vertical space is limited.
     • Protected stem threads: Since the threads are inside the valve body, they are less exposed to dirt, corrosion, and mechanical damage.
4. Resilient Seat
   • Description: The resilient seat is typically made from rubber (e.g., EPDM), which is molded onto the gate.
   • Benefits:
     • Provides a tight shutoff without metal-to-metal contact.
     • Reduces leakage and offers a longer lifespan due to its resistance to water hammer and fluid pressure surges.
5. Bonnet and Sealing System
   • Description: The bonnet is typically bolted to the valve body, with a sealing system using O-rings or gaskets to prevent leakage.
   • Benefits:
     • Easy to disassemble for maintenance and repairs.
     • Effective sealing to prevent leaks from the valve body.
6. Coating and Corrosion Protection
   • Description: Ductile iron valves are typically coated with fusion-bonded epoxy (FBE) or similar coatings to protect against corrosion, especially in potable water systems.
   • Benefits:
     • Provides superior corrosion resistance.
     • Ensures compliance with drinking water safety standards (e.g., NSF/ANSI 61 certification).