A slide gate deflector cone, referred to by Vortex as a Special Service Inlet (SSI), is an inexpensive deflector cone used in gravity flow applications that can extend the service life of your slide gate. The tapered deflector guides the material flow away from the gate’s inlet contact points, eliminating or reducing wear to the gate itself. The thin profile of the SSI (typically 3/16″ | 5mm) adds a minimal height to the gate’s profile, while the SSI extends inside the gate to just above the gate’s blade. The close proximity of the SSI to the blade ensures a cleaner seat and a tighter seal. For friable material, the SSI can be raised to help minimize the gate’s blade shearing of the material. The SSI can be manufactured for round, square, or rectangular gates, and can even be used as a transition from a round-to-square or square-to-round gate. The slide gate should be in the horizontal position for the inlet to work properly.

A Special Service Inlet is used for two primary purposes:

1. Prevent Abrasion to the Slide Gate-. This is done by directing material flow to the center of the gate, away from the sides and seal of the gate. The tapered ledge of the SSI serves as an umbrella where the abrasive material can repel against it. This shields the mouth of the gate from any wear from abrasive or coarse materials and the SSI becomes the wear piece. Even some fine powders can significantly wear the opening on a gate.

2. Prevent Material Packing – A Special Service Inlet also prevents material from being packed in the blade’s closure pocket or rammed into the end seal. Material on the leading edge of the blade falls away as the blade closely passes under the SSI. With no material, or a minimum of material, coming into contact with the gate’s seals, the seal life is extended significantly reducing the need for maintenance while maintaining a positive, dust tight seal.

The inexpensive cost of a Special Service Inlet can pay for itself many times over. Depending on the size of the gate, the SSI may be less than $100 or up to a few hundred dollars on very large gates. Gate cost may run from just a few hundred dollars to several thousand dollars, depending on size and construction. A SSI is essentially disposable and can be easily replaced multiple times over the life of a single gate. Also, the SSI helps to extend the life and performance of the seals. This helps you save time and lower maintenance costs by not having to take the gate out of service to replace the seals. In addition to, preventing a slide gate from becoming worn and leaking material also results in health and air quality benefits.

A Special Service Inlet can be on Vortex’s Orifice Gate, Roller Gate, Clear Action Gate, HDPV2, and Maintenance Gate. Some abrasive applications that Vortex has recommended a SSI for is handling ground coal, corn cobs, aqua feed, pebble lime, sand, slag and fly ash.

When considering using a SSI, you must remember that you are decreasing the circumference or area the material can flow. As a rule of thumb, a special service inlet will reduce the opening of the gate by about one gate size. If you have a 10″ roller gate, a square SSI with a .75″ | 20mm tapered lip will decrease the flow area by up to 1.5″ | 40mm. Relay the flow rates to your valve manufacturer who can help you determine the best size of valve and SSI for your gravity flow system.

By installing a Special Service Inlet on your gate valve, you can treat a SSI as a disposable piece at a relatively low cost compared to the cost of a new valve. This simple and inexpensive step will prolong the life of your slide gate.