In the second embodiment, although not shown, the check valve 7 shown in FIG 2 is housed in {HEAD ~ a connecting portion} between {TAIL ~ the pump unit} 6 and the casing 31 
between
In the second embodiment , although not shown , the check valve 7 shown in FIG 2 is housed in { HEAD ~ a connecting portion } between { TAIL ~ the pump unit } 6 and the casing 31
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH