产品名称：工式三阀组

产品型号：DCCH3 1151

所属类别：仪表阀组 >> 三阀组

所属系列：DC

安装尺寸图

工式三阀组

工式三阀组，通常简称为三阀组，是一种高度集成的过程仪表阀组，是差压变送器、差压式流量计等设备经典、常用的配套阀门。它由三个阀门（两个截止阀和一个平衡阀）共同铸造或加工在一个阀体上，结构紧凑，操作方便。

工式三阀组其核心作用是安全、正确地连接差压变送器与过程管道，并为仪表的投运、停运、零点校准和维护提供标准化的操作流程，核心目的在于保护精密的差压变送器膜片不被单向过压损坏。

工式三阀组主要特点与功能：

核心保护功能（平衡阀）： 三阀组独有的平衡阀能在操作两个截止阀之前或之后，瞬间平衡差压变送器正压室和负压室的压力，从而有效避免因引压管两侧压力不一致而导致的变送器膜片单向受压发生变形或损坏。

工式三阀组安全隔离： 两个截止阀（通常标记为“H”高压侧和“L”低压侧）可以分别隔离正负引压管，使得仪表能够在不中断工艺过程的情况下被安全地隔离、拆卸或校准。

工式三阀组标准化操作流程：

投运步骤： (1) 打开平衡阀 → (2) 缓慢打开高压侧截止阀 → (3) 缓慢打开低压侧截止阀 → (4) 关闭平衡阀。

停运步骤： (1) 打开平衡阀 → (2) 关闭低压侧截止阀 → (3) 关闭高压侧截止阀。

这个顺序是主要关键的，旨在通过先平衡压力来保护变送器。

工式三阀组紧凑与稳定： 一体化设计减少了法兰连接点，从而明显降低了潜在的泄漏风险，节省安装空间，并提高了系统的整体稳定性。

广泛应用： 主要用于需要测量差压、流量、液位的场合，遍布石油、化工、天然气、电力、水处理等几乎所有流程工业。

Product Overview of a 3-Valve Manifold

A 3-Valve Manifold, commonly simply referred to as a 3-Valve Manifold, is a highly integrated process instrument valve assembly. It is the most classic widely used accessory for differential pressure (DP) transmitters DP flow meters. It consists of three valves (two block valves one equalizing valve) cast machined into a single body, offering a compact structure convenient operation.

Its core purpose is to safely correctly connect a DP transmitter to the process piping to provide a standardized operating procedure for the instrument's commissioning, decommissioning, zero-point calibration, maintenance. The primary goal is to protect the sensitive diaphragm of the DP transmitter being damaged by over-pressure on one side.

Key Features Functions:

Core Protective Function (Equalizing Valve): The unique equalizing valve in a 3-valve manifold can instantly balance the pressure between the transmitter's high-pressure low-pressure chambers before after operating the block valves. This effectively prevents the transmitter's diaphragm being deformed damaged due to unilateral over-pressure caused by pressure imbalance in the impulse lines.

Safe Isolation: The two block valves (often marked "H" for high-pressure side "L" for low-pressure side) can isolate the high low impulse lines respectively, allowing the instrument to be safely isolated, removed, calibrated without interrupting the process.

Standardized Operating Procedure:

Commissioning Sequence: (1) OPEN the equalizing valve → (2) SLOWLY OPEN the high-pressure block valve → (3) SLOWLY OPEN the low-pressure block valve → (4) CLOSE the equalizing valve.

Decommissioning Sequence: (1) OPEN the equalizing valve → (2) CLOSE the low-pressure block valve → (3) CLOSE the high-pressure block valve.

This sequence is absolutely critical, designed to protect the transmitter by equalizing pressure first.

Compact Reliable: The integrated design reduces flange connections, significantly minimizing potential leak points, saving installation space, improving the overall reliability of the system.

Wide Application: Primarily used in applications requiring the measurement of differential pressure, flow, level. It is ubiquitous across almost all process industries, including oil & gas, chemical, natural gas, power generation, water treatment.