For example, {HEAD ~ the skirt valve} can be mounted about {TAIL ~ a stem} or post to create a 360 degree opening that is less likely to be jammed by solid items 
mounted about
For example , { HEAD ~ the skirt valve } can be mounted about { TAIL ~ a stem } or post to create a 360 degree opening that is less likely to be jammed by solid items
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH