Shell Valvata Oils J are quality refined, high viscosity mineral oils compounded with a small percentage of fatty oils. They are used, primarily, for the lubrication of steam cylinders working under high temperature, high pressure conditions, where low carbon formation and 'steam washing' are important considerations. They atomise more easily and with steam of moderate superheat and produce more tenacious lubricating films than 'straight' grades of the same viscosity.