Several seat and seal arrangements are available to address valve applications where performance during and immediately after a fire are a concern. 

The #7 (PTFE) and "A" (RPTFE) seat configurations offer "API 607 Tested" fire-safe performance. Flexible graphite or spiral wound gaskets are available for bonnet seals. Grafoil® in flat or EVSP 9000 style configurations provide the stem seals needed for fire safe applications.

Abrasive & Erosive Services

"Soft Seated" valves for abrasive services feature seat inserts which act as a buffer when the valve starts to open and as it nears the closed position. One design features inner and outer seat support rings, where the inner ring helps shield the seat insert from abrasives in the service. Another design features a one piece seatholder which completely confines the seat insert, and provides the same function in protecting the soft seat from abrasive particles in the flow stream.

In addition to the seat configuration options, resilient and rigid seat materials are available. The rigid seat choices include carbon-graphite, ceramic (used in conjunction with a ceramic ball) peek, and carbon reinforced peek.  Any of these options provide improved resistance to abrasion and erosion.  In addition, they extend the potential service range up to 1000°F when using #H carbon graphite seats.

For steam services, the #5 seat, a RPTFE containing 55% bronze and 5% molybdenum disulfide is an excellent choice as is the #4 carbon-graphite seat.

Valves for Chlorine Service

Valves intended for service in dry chlorine require specific alloy selections, design features, cleaning and testing procedures.

In accordance with the guidelines established by "The Chlorine Institute", Pamphlet 6-13th Edition (April 1993), Hastelloy trimmed carbon steel valves (model numbers starting with "CH") are suggested, and M35-1 trimmed carbon steel valves (model numbers beginning "CM") are the alternative for dry chlorine. All Hastelloy or M35-1 valves are also available.  Stainless steel valves or components are not recommended.

Selecting optional feature "HO" specifies a valve with the required vented body, specially cleaned and tested to comply with the requirements of Pamphlet 6.

Oxygen Service Valves

For this application, cleanliness is of utmost importance. Apollo Top Entry Valves specified for oxygen service (option "PO") are subjected to rigorous preparation procedures including special pre-cleaning and inspection followed by ultrasonic cleaning and more intense inspection. This insures the finished valve is free of burrs and sharp edges, as well as cleaned of hydrocarbon residues and particulate matter. Once valves destined for oxygen service enter Conbraco's clean room for preparation, they do not leave until they have been assembled, thoroughly tested, inspected, tagged and bagged to meet customer requirements.

High Temperature Service

For any applications utilizing metal, graphite, carbon graphite, peek, carbon reinforced peek, or a ceramic ball stop should be incorporated into the valve design (options "RU" and "AO"). These options are suggested at any temperature but it becomes a necessity above 500°F or when using ceramic or metal seats. The ball stop acts as a ball support and prevents the ball and seat from sliding down the 7° wedge when expansion, caused by the temperature increase, widens the wedge. If the ball were permitted to slide down the wedge, the valve would be locked tight when cooling and subsequent contraction. (This is specific to hard seated valves.)

When planning to insulate valves, consider using one of our stem extensions or one of the various extended version bonnets.  For fluctuating temperatures it may become necessary to vent the valve and/or (depending on application) select one of our live loaded bonnets.

High Cycle Service

The Top Entry Valve is our best choice for automation due to its ability to compensate for seat wear.  By selecting one of our live loaded style bonnets, the valve will then have self-adjusting stem packing.  Each of these features allow longer spans between routine maintenance.