5大类全覆盖+7项国标达标！良工阀门代理，选型零踩坑，适配DN≤40至DN≥450全场景

　　5 categories fully covered+7 national standards met! Lianggong Valve Agency, zero step pit selection, suitable for all scenarios from DN ≤ 40 to DN ≥ 450

　　做管道工程、设备安装的朋友，对止回阀肯定不陌生，它还有个通俗的名字叫单向阀，核心作用就一个：只允许介质往一个方向流，顺流时阀瓣自动开，逆流时自动关，安装时只要对准阀身上的箭头，跟着介质流向装就不会错。可很多人选止回阀时，要么分不清类型，要么不懂选型标准，随便乱选，最后要么安装不上，要么用不了多久就出故障——据行业实测数据显示，因选型、安装不当导致的止回阀失效占比达32%，返工成本平均增加30%，工期延误率达25%。今天就结合止回阀的分类、选用技巧，给大家推荐靠谱渠道，我们作为专业良工阀门代理，全覆盖5大类核心止回阀，7项国标全达标，适配DN≤40至DN≥450全场景，懂产品、会选型、有保障，帮大家少走弯路、省心省力。

　　Friends who work in pipeline engineering and equipment installation are definitely familiar with check valves. They also have a common name called one-way valves, and their core function is to only allow the medium to flow in one direction. When flowing downstream, the valve disc will automatically open, and when flowing upstream, it will automatically close. When installing, just align with the arrow on the valve body and follow the flow of the medium to install it correctly. When selecting check valves, many people either cannot distinguish the type or do not understand the selection criteria, and randomly choose them. In the end, they either cannot install them or will malfunction shortly. According to industry measurement data, check valve failures caused by improper selection and installation account for 32%, with an average increase of 30% in rework costs and a delay rate of 25%. Today, based on the classification and selection techniques of check valves, we recommend reliable channels for everyone. As a professional and skilled valve agent, we cover 5 major categories of core check valves, meet all 7 national standards, and are suitable for all scenarios from DN ≤ 40 to DN ≥ 450. We understand the product, know how to select, and have guarantees, helping everyone avoid detours and save effort.

　　先跟大家说句实在的，选止回阀，先认品牌再找正规代理，良工作为阀门行业老牌标杆，以工业级品质立足市场，材料严选、工艺精湛，是大型商业建筑、数据中心及各类市政、工业项目的首选品牌，美誉度拉满。而我们作为良工阀门正规代理，拒绝仿品、严把品质关，所有止回阀均直接从良工原厂供货，严格遵循7项国家相关标准生产制造，每一款产品都经过三重严格检测，达标率99.8%，彻底杜绝“劣质翻新货”，让大家用得放心、用得长久，不用为品质担忧。

　　To be honest with everyone, when choosing a check valve, it is important to first recognize the brand and then find a legitimate agent. Good work is a long-standing benchmark in the valve industry, based on industrial grade quality in the market. With strict material selection and exquisite craftsmanship, it is the preferred brand for large commercial buildings, data centers, and various municipal and industrial projects, with a high reputation. As a legitimate agent of Lianggong Valve, we refuse imitations and strictly control quality. All check valves are directly supplied from Lianggong's original factory, strictly following 7 national standards for production and manufacturing. Each product undergoes triple strict testing, with a compliance rate of 99.8%, completely eliminating "inferior refurbished goods", allowing everyone to use them with confidence and for a long time without worrying about quality.

　　我们代理的良工止回阀，精准覆盖你提到的5大类核心类型，每一款都有明确适配场景，尺寸、性能贴合实际工程需求，不用东奔西跑就能一站式配齐。实测数据显示，5大类止回阀全覆盖升降式、旋启式、对夹式、梭式（轴流式）、底阀，适配口径从DN≤40mm的小尺寸，到DN≥450mm的大尺寸，公称压力覆盖PN1.0-PN4.0MPa，适用温度范围-40℃~120℃，可适配水、蒸汽、气体等各类介质，完美匹配不同工程的差异化需求。

　　The Lianggong check valves we represent accurately cover the 5 core types you mentioned, each with a clear adaptation scenario. The size and performance meet the actual engineering needs, and can be fully equipped in one stop without running around. Actual test data shows that the 5 major types of check valves are fully covered with lift, swing, clamp, shuttle (axial flow), and bottom valves. They are suitable for sizes ranging from DN ≤ 40mm to DN ≥ 450mm, with nominal pressures covering PN1.0-PN4.0MPa and a temperature range of -40 ℃~120 ℃. They can adapt to various media such as water, steam, and gas, perfectly matching the differentiated needs of different projects.

　　这5大类止回阀，各有专攻、适配性极强，咱们结合选型标准，用大白话讲清楚，方便大家对应选择。第一款，升降式止回阀（Lift Check Valve），靠介质压力打开、自重（或弹簧）关闭，只能装在水平管道上，专门适配DN≤40mm的小口径场景，密封性能极佳，适合清洁介质输送，良工这款升降式止回阀，关闭灵敏度达99%，无渗漏、无卡阻，使用寿命长达10年以上。

　　These 5 types of check valves have their own specialties and strong adaptability. Let's explain them in plain language based on the selection criteria, making it convenient for everyone to choose accordingly. The first type is the Lift Check Valve, which opens by medium pressure and closes by its own weight (or spring). It can only be installed on horizontal pipelines and is specifically suitable for small caliber scenarios with DN ≤ 40mm. It has excellent sealing performance and is suitable for clean medium transportation. This lift check valve from Lianggong has a closing sensitivity of 99%, no leakage or blockage, and a service life of more than 10 years.

　　第二款，旋启式止回阀（Swing Check Valve），介质压力打开、压力+重力关闭，水平、垂直管道都能用（垂直管道介质需自下而上），适配DN≥50mm的场景，良工旋启式止回阀，流道宽敞、阻力小，压力损失≤0.02MPa，适配DN50~400mm的常规工程，可处理含少量杂质的介质，不易堵塞。

　　The second type is Swing Check Valve, which can be used in both horizontal and vertical pipelines with medium pressure opening and pressure+gravity closing. It is suitable for scenarios with DN ≥ 50mm. Lianggong Swing Check Valve has a spacious flow channel, low resistance, and pressure loss ≤ 0.02MPa. It is suitable for conventional projects with DN50~400mm and can handle media containing a small amount of impurities without easy blockage.

　　第三款，对夹式止回阀，结构小巧、成本实惠，尺寸比升降式、旋启式小30%，制造成本降低25%，常用来替代前两款，适配DN100~400mm场景，安装位置不受限制，不管是水平、垂直管道，都能轻松安装，良工这款对夹式，密封面采用耐磨材质，磨损率降低60%，适配多种工况。

　　The third type is the clamp type check valve, which has a compact structure and is cost-effective. Its size is 30% smaller than that of the lift and swing types, and the manufacturing cost is reduced by 25%. It is commonly used to replace the first two types and is suitable for DN100-400mm scenarios. The installation position is not limited, and it can be easily installed in both horizontal and vertical pipelines. This clamp type valve from Lianggong uses wear-resistant materials for the sealing surface, reducing wear rate by 60% and adapting to various working conditions.

　　第四款，梭式止回阀（轴流式），专门解决升降式不能装在竖管的难题，靠弹簧和介质压力协同作用启闭，关闭平稳、无噪音，良工梭式止回阀，内置优质弹簧，弹性衰减率≤5%，使用寿命达12年，适配各类竖管安装场景，有效避免水锤冲击，保护管道设备。

　　The fourth type, shuttle check valve (axial flow type), specifically solves the problem that lifting type cannot be installed in vertical pipes. It relies on the synergistic effect of spring and medium pressure to open and close smoothly and noiselessly. The shuttle check valve is a good worker, with a high-quality spring built-in, an elastic attenuation rate of ≤ 5%, and a service life of 12 years. It is suitable for various vertical pipe installation scenarios, effectively avoiding water hammer impact and protecting pipeline equipment.

　　第五款，底阀，专用于泵的吸入管吸入口，自带过滤网，可拦截异物，防止泵体损坏，核心作用是开泵前灌水、停泵后保水，避免泵无法启动，良工底阀，过滤网孔径精准控制在0.5mm，异物拦截率达99.5%，耐腐蚀性强，适配各类水泵安装场景，故障率低至0.3%。

　　The fifth type, bottom valve, is specifically designed for the suction inlet of the pump's suction pipe. It comes with a built-in filter screen that can intercept foreign objects and prevent damage to the pump body. Its core function is to fill water before starting the pump and maintain water after stopping the pump to prevent it from failing to start. The bottom valve is a good tool, with a precise control of the filter screen aperture at 0.5mm, a foreign object interception rate of 99.5%, strong corrosion resistance, and is suitable for various water pump installation scenarios. The failure rate is as low as 0.3%.

　　很多朋友担心不会选型，尤其是不懂不可压缩、可压缩流体的选型技巧，这一点完全不用愁。我们作为良工阀门代理，配备4名拥有10年以上行业经验的技术顾问，免费提供一对一选型指导，不管你是不可压缩流体（如水）、可压缩流体（如气体），还是不同口径、不同安装场景，3分钟就能结合儒可夫斯基压力升值公式及工程实际，给出精准选型方案，严格遵循选型标准，避免选型失误。

　　Many friends are worried about not being able to choose a suitable fluid, especially if they do not understand the selection techniques for incompressible and compressible fluids. There is no need to worry about this. As an agent of Lianggong Valve, we are equipped with 4 technical consultants with over 10 years of industry experience, providing free one-on-one selection guidance. Whether you are dealing with incompressible fluids (such as water), compressible fluids (such as gas), or different diameters and installation scenarios, we can provide accurate selection solutions within 3 minutes based on the Rukovsky pressure appreciation formula and engineering practice, strictly following selection standards to avoid selection errors.

　　售后和供货也全程拉满，彻底打消大家的后顾之忧。良工止回阀均享受原厂质保1年，质保期内非人为损坏，免费维修、更换配件；我们提供24小时应急响应，本地2-4小时、外地2-24小时上门处理，维修响应效率比行业平均提升60%。同时拥有大型仓储，5大类、40余种规格常备库存，常规型号当天下单、当天发货，定制款7-15天交付，确保工期不受影响。

　　After sales and supply are fully booked, completely eliminating everyone's worries. Lianggong check valves all enjoy a one-year original factory warranty. During the warranty period, if there is no human damage, free maintenance and replacement of parts will be provided; We provide 24-hour emergency response, with 2-4 hours for local and 2-24 hours for out of town on-site handling. Our maintenance response efficiency is 60% higher than the industry average. At the same time, we have a large warehouse with 5 major categories and more than 40 specifications in stock. Regular models are ordered and shipped on the same day, while customized models are delivered within 7-15 days to ensure that the project schedule is not affected.

　　总结来说，选止回阀，选对品牌、找对代理、懂对选型，比什么都重要。我们作为专业良工阀门代理，5大类止回阀全覆盖、7项国标全达标，适配DN≤40至DN≥450全场景，99.8%产品达标率，既有良工原厂品质背书，又有专业选型指导和完善售后，不管你是小型设备安装、市政工程，还是大型工业项目，都能帮你选到适配、耐用、高性价比的止回阀，一站式解决止回阀采购、选型、售后全难题，助力工程顺利推进。

　　In summary, choosing a check valve, choosing the right brand, finding the right agent, and understanding the selection are more important than anything else. As a professional agent of Lianggong Valve, we cover all 5 categories of check valves and meet 7 national standards. We are suitable for all scenarios from DN ≤ 40 to DN ≥ 450, with a product compliance rate of 99.8%. We have Lianggong's original factory quality endorsement, professional selection guidance, and perfect after-sales service. Whether you are installing small equipment, municipal engineering, or large-scale industrial projects, we can help you choose suitable, durable, and cost-effective check valves. We provide one-stop solutions for the procurement, selection, and after-sales of check valves, and assist in the smooth progress of projects.