Why pull type solenoid exhaust gas recirculation valve is not avail in the market ?

Why all companies go for push type solenoid EGR valve ?|||I'd say the most common reason would be deposits on the valve over time. With a push type valve, a good portion of the shaft is covered, preventing deposits from forming on the shaft, which would cause it to stick. With a pull type valve, the pintle would be moving backwards across deposits, making it more likely to stick over time.