Bottom valve and components prevent accidental product loss.

Union Tank Car Company's DOT117J100W allows gravity unloading through a 4" full port, low profile, stainless steel ball valve. The valve application integrates skid protection and a disengaging handle to ensure the valve stays closed during transit.

The valve opens when an operator engages the handle to rotate the ball and align its port vertically, in line with the outlet nozzle. When the ball is turned back 90 degrees to the horizontal position, the valve closes interrupting product flow. The highly finished ball is compressed between two seals, which are typically a variation of Teflon, opposite the ball seat in the valve body and retainer. The valve body is a cast housing with a machined seat for the ball seal. The ball stem is encased in a soft seal to ensure that it holds commodity. Union Tank Car Company's standard design allows direct steam application through the valve's integral jacket. Heating the valve body promotes the flow and a more rapid unloading of denser liquids.

The valve body is engineered for a tongue-and-groove match with a steel saddle that is welded to the tank shell. The low profile design results in the valve being slightly recessed into the tank saddle and skid arrangement, but still flush with the tank shell to allow unloading. The protection is fortified with a skid that is welded to the tank shell. The skid shear point protects the valve bodies. This robust system averts commodity loss by allowing the nozzle and secondary valves to shear away in the event the tank separates from the truck during an incident.

The bottom valve is fitted with a 4" AAR threaded nozzle that accepts an auxiliary valve, if necessary. The bottom outlet nozzle requires a cap-and-plug assembly that is chained to the protective skid. All UTLX cars are equipped with various layers of protection to ensure the safety of your products and our environment, including the important low profile bottom valve, protective skid, and disengaging handle.


  • 1 Protective Skid
  • 2 Teflon Seals
  • 3 Saddle
  • 4 Disengaging Handle Assembly
  • 5 Ball Stem
  • 6 Low Profile Bottom Valve
  • 7 Outlet Nozzle
  • 8 Chained Cap & Plug Assembly