对焊式止回阀是防止介质倒流，是一种依靠介质压力开启和关闭的自动阀门.主要适用于CNG高压气体 高压液体及压力试验泵上。由于对焊式止回阀的结构长度比一般法兰式止回阀短，对有安装空间限制的场所非常适用。对焊式止回阀具有结构长度短，体积小重量轻，阀瓣关闭快速，水锤压力小，流道通畅，流体阻力小，水平管道或垂直管道均可使用，安装方便，动作灵敏,密封性能好，阀瓣行程短、关阀冲击力小，简单紧凑、造型美观，使用寿命长、可行性高，防止介质倒流，自动控制等优点。

对焊式止回阀

对焊式止回阀，也称为对焊连接逆止阀或单向阀，是一种依靠介质自身力量自动启闭的阀门。当介质顺向流动时，阀瓣在流体压力下开启；当介质停止或逆向时，阀瓣在自重、弹簧力（若适用）及反向压力作用下关闭，从而有效防止介质倒流。

对焊式止回阀其主要特点包括：

· 连接方式：阀体两端采用对焊连接，与管道直接焊接，结构紧凑，密封稳定，适用于高压、高温管道系统。

· 结构类型：主要有旋启式（如H64H型，阀瓣绕销轴旋转）和升降式（如H62Y型，阀瓣沿垂直通道中心线升降）两种。

· 适用工况：广泛应用于石油、化工、电力、冶金等行业的高温、高压管道系统，以及城市供热和供水系统。

对焊式止回阀主要技术内容

1. 产品特点

· 结构紧凑：对焊连接使其结构长度短、体积小、重量轻，便于安装和布置管道，节省材料。

· 密封稳定：

  · 许多型号采用压力自紧式密封，中腔密封压力随介质压力升高而增强。

  · 阀瓣和阀座密封面常采用司太立（Stellite）钴基硬质合金堆焊或类似耐磨材料（如H62Y型采用钴基硬质合金等离子喷焊），耐磨、耐高温、耐腐蚀，使用寿命长。

· 流阻小，性能稳定：旋启式全开时流体压力几乎不受阻碍。部分阀门（如CVWR型）采用流体型设计以减小水头损失。

· 对焊式止回阀维护简便：部分结构（如H64Y型）提供螺栓连接、缠绕垫片密封式阀盖等多种阀盖设计选项，便于维护。

2. 对焊式止回阀主要技术参数

对焊式止回阀项目 参数/描述

公称压力 (PN) 常见范围 PN1.6 - PN45.0 MPa (或 Class 150 - 2500)

公称通径 (DN) DN15 ~ DN900 (或 NPS 1/4" ~ 36")

连接形式 对焊 (Butt Welding)，部分小口径也可采用承插焊

适用介质 水、蒸汽、油品、气体及其他腐蚀性或非腐蚀性介质

适用温度 约 -29℃ ~ 550℃ (具体取决于阀体材质和密封材料，例如碳钢适用温度约-29℃～425℃，合金钢适用温度约-29℃～550℃)

阀体材料 碳钢 (如 WCB, A105)、不锈钢 (如 304, 316, 316L)、合金钢 (如 WC6, WC9, F22)

设计制造标准 参考 GB12235, ASME B16.34, MSS SP-118, API 598 等

3. 对焊式止回阀主要零件材料（示例）

以H64Y对焊旋启式止回阀的常见材料配置为例：

序号 零件名称 碳钢 (CS to ASTM) 合金钢 (AS to ASTM) 不锈钢 (SS to ASTM)

1 阀体 (Body) A105 A182 F22 A182 F304(L) / F316(L)

2 阀瓣 (Disc) A276 420 A276 304 A276 304(L) / 316(L)

3 阀座 (Seat) A276 410 A276 304 A276 304(L) / 316(L)

4 螺栓 (Bolts) A193 B7 A193 B16 A193 B8 / B8M

4. 对焊式止回阀典型应用领域

· 石油和天然气工业

· 化工和制药工业

· 电力和冶金工业

· 城市供热和供水系统

Butt Welding Check Valve Product Overview  Full Content Translation

1. Product Overview

The Butt Welding Check Valve, also known as a butt welding non-return valve  single-direction valve, is an automatic valve that relies on the force of the medium itself to open  close. It allows medium to flow in one direction  prevents backflow. When the medium flows forward, the disc opens under fluid pressure; when the medium stops  reverses, the disc closes automatically under its own weight, spring force (if applicable),  reverse pressure, effectively preventing backflow  protecting system equipment.

Its main features include:

· Connection Method: Both ends of the valve body feature butt welding connections, allowing direct welding to the pipeline. This results in a compact structure  reliable sealing, making it suitable for high-pressure  high-temperature pipeline systems.

· Structural Types: Primarily include the Swing Type (e.g., Model H64H,  the disc rotates around a pin)  the Lift Type (e.g., Model H62Y,  the disc moves up  down along the vertical centerline of the passage).

· Suitable Applications: Widely used in high-temperature, high-pressure pipeline systems in industries such as petroleum, chemical, power generation, metallurgy, as well as in urban heating  water supply systems.

2. Main Technical Content

2.1 Product Features

· Compact Structure: The butt weld connection gives it a short face-to-face dimension, small volume,  light weight, facilitating installation, handling,  pipeline layout, while saving material.

· Reliable Sealing:

  · Many models utilize a pressure self-tightening seal,  the sealing pressure in the middle cavity increases with higher medium pressure.

  · The disc  seat sealing surfaces often employ Stellite cobalt-based hard alloy overlay welding  similar wear-resistant materials (e.g., Model H62Y uses cobalt-based hard alloy plasma spray welding), making them wear-resistant, high-temperature resistant, corrosion-resistant,  ensuring a long service life.

· Low Flow Resistance, Stable Performance: In the fully open position of swing check valves, fluid pressure is almost unimpeded. Some valves (e.g., CVWR type) feature a hydrodynamic design to minimize head loss.

· Easy Maintenance: Some designs (e.g., H64Y type) offer various bonnet design options like bolted bonnet with spiral-wound gasket for easier maintenance.

2.2 Main Technical Parameters

The table below lists typical technical parameters(Please note that specific values may vary depending on the model, standard,  manufacturer):

Item Parameter/Description

Nominal Pressure (PN) Common range PN1.6 - PN45.0 MPa ( Class 150 - 2500)

Nominal Diameter (DN) DN15 ~ DN900 ( NPS 1/4" ~ 36")

Connection Type Butt Welding; some small-bore valves may also use Socket Welding

Applicable Media Water, Steam, Oil products, Gas,  other corrosive  non-corrosive media

Applicable Temperature Approx. -29°C ~ 550°C (Specifically depends on body material  sealing materials; e.g., Carbon steel approx. -29°C～425°C, Alloy steel approx. -29°C～550°C)

Body Material Carbon Steel (e.g., WCB, A105), Stainless Steel (e.g., 304, 316, 316L), Alloy Steel (e.g., WC6, WC9, F22)

Design & Manufacture Standards Refer to GB12235, ASME B16.34, MSS SP-118, API 598, etc.

2.3 Main Part Materials (Example)

Taking the common material configuration of the H64Y Butt Welding Swing Check Valve as an example:

No. Part Name Carbon Steel (CS to ASTM) Alloy Steel (AS to ASTM) Stainless Steel (SS to ASTM)

1 Body A105 A182 F22 A182 F304(L) / F316(L)

2 Disc A276 420 A276 304 A276 304(L) / 316(L)

3 Seat A276 410 A276 304 A276 304(L) / 316(L)

4 Bolts A193 B7 A193 B16 A193 B8 / B8M

2.4 Typical Application Fields

· Petroleum  Natural Gas Industry

· Chemical  Pharmaceutical Industry

· Power Generation  Metallurgical Industry

· Urban Heating  Water Supply Systems