Ukutshintsha koxinzelelo lwe-HW18 kusetyenziselwa ukulawula uxinzelelo lwetanki phakathi kwamaxabiso amabini okusetwa kwangaphambili kwi-3 isigaba se-3 eqhutywa ngombane yoxinzelelo lomoya. Zifumaneka ngevalve yokukhupha umthwalo, ethintela i-compressors ukuba iqale phantsi komthwalo, kwaye iyafumaneka nge-Off-Off knob yokusikwa ngesandla.

Iiswitshi zoxinzelelo zeHW19 zisetyenziselwa ukulawula uxinzelelo lwetanki phakathi kwamaxabiso amabini asetwe kwangaphambili kwiicompressor zomoya eziqhutywa ngumbane. Zifumaneka ngevalve yokukhulula, ethintela iicompressors ukuba ziqale phantsi komthwalo kwaye ziyafumaneka nge-Off knob yokusikwa ngesandla kwecompressor.

Ukutshintsha koxinzelelo lwe-HW20 kusetyenziselwa ukulawula uxinzelelo lwetanki phakathi kwamaxabiso amabini asetwe kwangaphambili kwiicompressor ezincinci zombane. Zixhotyiswe ngevalve yokukhulula, zinokuthintela iicompressors ukuba ziqale phantsi komthwalo.I-auto-off qhawula i-lever ye-manual cut off the comressor. Zombini enye kunye nesine-izibuko isitayile ezininzi ziyafumaneka ebonelela ukunyuswa lula kweevalvu kunye neegeyiji.