Which gate valve is better?

02

The following expert spindle checks require additional testing which may or may not be provided by the manufacturer:
 

Tip 6: Spindle material

• Confirm that the spindle material of the gate valve matches what is claimed by the manufacturer. This can be done using a spectrometer, which provides a break-down of a material’s chemical composition.
   
• Based on the chemical composition, you can then calculate or look up the pitting resistance equivalent number (PREN), a reliable indicator for through-wall corrosion resistance. As a general rule, if you are unsure about the corrosivity of the water and/or the soil around your valve, you should choose a spindle material with a PREN value of 25 or greater.

The spindles of Hawle E3 gate valves are cold-rolled, also on the shaft, thereby achieving extremely smooth surfaces. This preserves the wedge nut as well as the spindle sealing O-rings.