防倒流装置

产品概述

The Copper Double Check Backflow Preventer is a compact anti‑backflow device featuring a high‑quality brass body and two independent check valves connected in series with no intermediate relief chamber. It is specifically designed to prevent low‑hazard, non‑health‑threatening media (such as slightly contaminated water, air conditioning water, industrial recirculating water, etc.) from flowing back into the upstream potable water supply. This device is a double check valve (DC) type, conforming to EN 1717 and ASSE 1015 standards, and is suitable for low‑risk (non‑toxic, non‑carcinogenic) backflow prevention applications.

Compared with reduced pressure zone (RPZ) backflow preventers that incorporate a relief chamber, this product offers extremely low flow resistance, no water discharge, no water waste, and simple installation. The body is forged or cast from brass (CW617N or HPb59‑1) with female threaded ends. Available in nominal diameters from DN15 to DN65, it is widely used in small to medium bore piping systems for residential and commercial buildings, air conditioning, boiler makeup water, landscape irrigation, and similar applications.

产品结构

The Copper Double Check Backflow Preventer mainly consists of the following parts:

1. 阀体: Forged or precision cast brass (CW617N, HPb59‑1, or DZR dezincification‑resistant brass). Female threaded ends (NPT, BSPT, BSPP, or G threads).

2. 第一止回阀（上游）: Spring‑loaded lift type check valve with a rubber soft seal (NBR/EPDM).

3. 第二止回阀（下游）: Same construction as the first, installed in series within the body to provide dual sealing redundancy.

4. 弹簧组件弹簧：不锈钢（304/316）螺旋弹簧，提供初始关闭力并确保快速响应。.

5. 测试旋塞（可选）: Test ports located in the chamber between the two check valves (brass or stainless steel) for field verification of each check valve’s sealing performance.

6. 阀盖: Removable brass bonnet for easy maintenance and cleaning of internal cartridges.

All internal parts can be accessed from the bonnet side. With no intermediate relief chamber, the flow path is simple and pressure loss is minimal.

功能

1. 防止背压回流工作原理：当下游压力超过上游压力时，两个止回阀同时关闭，利用弹簧力和反向压力形成双重密封，阻止回流。.

2. 防止虹吸回流：当上游压力急剧下降至负压状态时，两个止回阀快速关闭，切断来自下游介质的任何虹吸回流。.

3. 低阻力运行低阻力运行：由于无中间泄压腔，流道畅通无阻，压降典型值≤0.15 bar，适用于连续流动系统，可显著节能。.

4. 冗余密封保护：两个独立止回阀提供故障安全保护——即使一个阀瓣被杂物轻微卡住或其密封老化泄漏，另一级仍能保持密封，防止回流。.

5. 无排水无排水：与RPZ型不同，本产品在正常运行期间不排水，因此无水资源浪费，也无需排水管道。.

6. 在线测试：无需将阀门从管道上拆下，即可利用测试旋塞单独测试每个止回阀的密封完整性。.

7. 任意角度安装: Springs provide initial sealing force, allowing horizontal or vertical installation (vertical requires upward flow).

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工作条件

1. 适用介质：自来水、空调冷却水、供暖热水、工业循环水、游泳池补充水、灌溉水、消防水、轻度污染水（非粪便、非有毒化学品）。.

2. 温度范围适用温度：0°C 至 +80°C（标准 EPDM 密封件）；–20°C 至 +120°C（FKM 密封件）。.

3. 压力等级公称压力：PN10, PN16 (Class 125, Class 150)。.

4. 公称通径: DN15, DN20, DN25, DN32, DN40, DN50, DN65 (1/2″ – 2½”).

5. 安装位置安装方向：水平（推荐）或垂直（流向向上）。.

6. 典型应用:

   1. 住宅和商业建筑生活用水入户管道（防止家庭用水回流至市政管网）

   2. 空调冷冻水/冷却水补水管道

   3. 小型锅炉及太阳能热水器补水

   4. 景观灌溉取水点

   5. 游泳池和观赏池塘的补充水

   6. 消防系统辅助供水连接

   7. 食品厂非直接接触工艺补水

 总结

The Copper Double Check Backflow Preventer, with its high‑quality brass corrosion‑resistant body, series dual check valve redundant design, extremely low flow resistance, no water discharge, and easy threaded installation, is a cost‑effective anti‑backflow solution for low‑health‑hazard (non‑toxic contamination) applications. Compared with reduced pressure zone (RPZ) types, it has no intermediate relief chamber, resulting in lower pressure loss, no water waste, and simpler installation – making it particularly suitable for continuous flow systems with strict pressure drop requirements in small to medium bore pipelines.

The product meets international and national backflow prevention standards and is widely used in residential, commercial, irrigation, and industrial makeup water systems. For pipeline systems that need to prevent non‑health‑hazard backflow while pursuing low operating costs, the Copper Double Check Backflow Preventer is an ideal core protection device.