STP21 Direct-Acting Solenoid Valve

Model: STP21-15 Category: STP Series

Product Overview

The STP21 direct-acting solenoid valve adopts a direct-acting structure where the solenoid coil directly drives the valve core to open and close, operating without relying on medium pressure differential, achieving zero pressure differential start. Port sizes 1/8, 1/4, 3/8 inch, bore DN4-DN10, pressure 0-10bar, suitable for fluid control under small bore, low pressure differential or zero pressure differential conditions.

Technical Parameters

ParameterValue
BoreDN4-DN10 (1/8, 1/4, 3/8 inch)
Working Pressure0-10bar (zero pressure differential start)
Working Temperature-5C to 80C
Valve Body MaterialBrass / Stainless Steel
VoltageAC220V / DC24V
Seal MaterialNBR / EPDM / PTFE
Action ModeNormally Closed / Normally Open (optional)
ConnectionInternal Thread

Product Features

  • Zero pressure differential start: operates without medium pressure differential, suitable for vacuum and low pressure conditions
  • Direct-acting structure: extremely fast response, reliable operation
  • Small bore design: suitable for precision flow control
  • Simple structure, easy maintenance
  • Normally closed / normally open types available
  • Material options: brass or stainless steel

Selection and Installation Guide

  • For zero or low pressure differential conditions, direct-acting type is preferred
  • Select port size based on flow requirements (1/8, 1/4, 3/8 inch)
  • For large bore and high flow conditions, pilot-operated type is recommended
  • Install with valve body arrow aligned with fluid flow direction
  • Install coil vertically upward to avoid liquid accumulation
  • When medium contains impurities, install a filter before the valve
  • Keep voltage fluctuation within +/-10%