The ROSS Poppet Valve ....a ROSS specialty from the beginning

Positive Sealing

確実なシール性 Inlet air pressure forces the inlet pop-pet upward, pushing the poppet seal firmly against the seat. The higher the inlet pressure, the greater is the sealing force. Note that the seal is engaged perpendicular to the seat; there is no sliding action to damage and wear the seal.

Self Cleaning

セルフクリーニング機能 The flow velocity for a given volume of air is dependent upon the area through which it is flowing. The smaller the area, the greater the velocity.

In our poppet valves, the smallest flow-through area is across the poppet's seal and seat. This produces a very high velocity which blows all dirt and foreign matter out of the seat area for a virtually leak-proof seal.

Self-Compensating for Wear

シール部の自己補正機能 Because of the poppet valve's design, any change in the height of the valve seal (due to burnishing) is automatically compen-sated for by an equal change in the length of stroke.>

Therefore, the sealing force remains constant over the entire life of the valve.

Sure Shifting

確実な切替動作 Pilot air pressure, working on a large pis-ton, produces a very strong actuating force.

High velocity air flow begins at the instant when the inlet poppet moves off the seat; flow enhances actuation right from the start.

There is minimal sliding of seals in a poppet valve (sliding seals are highly prone to varnish).

When pilot air is exhausted, the inlet pree-sure produces an extremely strong up-ward force, reliably shifting the valve to a closed position.

Table -Comparison- 27series with 21 series

Items 27 series 21 series
Condition to use Normal Low Temp. High Temp Vacuum
Temp Ambient [℃] 4 to 50 -40to 50 -17to 122 -40to 50
Media [℃] 4 to 80 -40to 80 -17to 150 -40to 80
Main material of internal Acetal resin Aluminum alloy/Stainless steel
Seal Material Piston seal NBR (Buna-N) NBR (Buna-N) FKM NBR (Buna-N)
Inlet seal Polyurethane NBR (Buna-N) FKM NBR (Buna-N)
Exhaust seal NBR (Buna-N) NBR (Buna-N) FKM NBR (Buna-N)
Bushing material Nylon Nylon Polimide Nylon
Material of manual override NBR (Buna-N) Aluminum alloy
Pipe size Exhaust port 1/2"~1-1/2" 1-1/2"~2-1/2" 1/2"to1-1/2" 1/2"to2-1/2"
In & Outlet port 1/4"~1-1/2" 1-1/2"~2-1/2" 1/4"to1-1/2" 1/4"to2-1/2"
Pressure Supply [MPa] 0.1 to 0.98 0.2 to 0.98 0.2 to 0.98 Vacuum to 0.98
Pilot supply Internal and External Internal and External External