Metal-Seated Ball Valve Applications

Emerson’s Shawn Fagen, Zach Stahlin and Mark Nymeyer teamed up on an Emerson Exchange presentation, Heavy Metal – Turn up your Z500 Knowledge to Eleven! I was expecting to need earplugs but instead found out that their abstract was:

This session is an introduction for the end user to the newly introduced Fisher Z500, metal-seated ball valve. The Z500 valve is a simplistic two-piece floating ball design with integral metal seat meant to provide tight metal seated shutoff in high temperature, high pressure, corrosive, and erosive applications across all industries. These valves are used in applications where tight shutoff is needed to protect critical plant assets. Highlights will include product overview, Power and Refining applications and best practices.

The Fisher Z500 Metal Seated Ball Valve Isolation valves join the Fisher Severe Service platform of valves for severe service NPS ½ – 36 on-off applications. Pressure classes range from 150-4500. It is rated for the standard leak test to API 598 in the preferred flow direction. Here are some additional specifications:

  • Temperatures up to 1400°F
  • High Pressure up to Class 4500
  • Corrosive and Erosive Media Slurry Service
  • Leakage rates of API 598 (Standard)
  • FCI 70-2 Class VI / ISO 5208 Rate A (optional)
  • Typically designed to B16.34

Common applications in the power industry include:

  • Condensate and Condenser Drain
  • Economizer Drain
  • Main Steam Vent and Drain
  • Preheat and Reheat Drain
  • Superheated Steam Drain
  • Turbine Drain

In these applications, leakage through the seat, stem packing and body halves can mean loss of generated steam, valve, pipe, or actuator damage, and potential personnel safety hazardous conditions.

The Z500 valve integral seat eliminates leak path. Also, fixed valve centerlines help minimize stem and packing wear. And, proper material selection and body gasket design to withstand the requirements of the application.

Common applications in the refining industry include drum blow down / warm-up, overhead vapor lines, drum switching & bypass and furnace & strainer isolation. Challenges include high temperatures and abrasive fluids that can solidify. To address these challenges, the valve is designed with scraper seats, purge ports, large actuator safety factor and proper material selection.

Here’s a link to the Z500 valve product data sheet.

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