---
publication_id: "OT-2026-000000111"
title: "Suck-back valve"
published_at: "2026-09-15T19:02:30.074893Z"
canonical_url: "https://opentechnical.org/p/OT-2026-000000111"
categories:
  - "industrial-motion-power-transmission/fluid-power"
keywords:
  - "f16k23/00"
  - "f16k7/12"
---

# Suck-back valve

## Abstract

A suck-back valve includes a valve main body formed with a suck-back chamber, and a suck-back mechanism unit. The suck-back mechanism unit includes a suck-back piston accommodated in a suck-back cylinder chamber and being slidable between two dead center positions, and a biasing member biasing the suck-back piston in a direction to increase the volume of the suck-back chamber. The suck-back cylinder chamber is divided by the suck-back piston into a first fluid chamber and a second fluid chamber. The biasing member is arranged in the first fluid chamber, and a standby position at which the suck-back piston is positioned when the pressure of a drive fluid in the second fluid chamber becomes the maximum is set to be away from the dead center position on the side closer to the suck-back chamber.