Valve, Low Suction Throttling : A pilot-operated valve installed in discharge piping that maintains positive pressure in the suction piping, while monitoring pressure in the suction piping through a sensing line
NFPA 20 Standard for the Installation of Stationary Pumps for Fire Protection, 2007 ed. http://www.saltech.co.il/_Uploads/dbsAttachedFiles /NFPA_20.pdf, (Std: Instll of Stnry Pumps for Fr Prac - Amer) {188 NFC}