德国苏尔达特种阀门有限公司（Schroedahl）是一家在世界范围内知名度很高的特种阀门专业制造商；特别是在泵保护领域，始终具有世界领先之技术。从1962年成立至今，苏尔达一直致力于产品的研发、创新，制造技术随着严格的质量控制措施的认真执行不断的得以提升，已成为全球特种阀门行业的领先者。

60多年以来，苏尔达先后取得了AD-HP0 und DIN EN ISO 3834、 DGR 97/23/EG、 DIN ISO 9001、 KTA1401、 ISO 14001 、 KTA-RWE等一系列国际先进认证；目前已经交付了60000多个阀门，以满足世界各地的客户。产品广泛应用于电力、钢铁、能源、化工、石油、天然气、海洋钻井平台等行业和领域，深得广大用户的拥护和认可。我司为德国苏尔达阀门有限公司在中国地区代表处，负责苏尔达阀门在中国境内的销售、技术支持、售后服务等工作。

苏尔达产品主要分为泵保护阀和特种控制阀。

苏尔达泵保护阀的基理和功能：

（一）原理：

泵保护阀的功能是确保泵的最小流量，以避免因过热和气蚀导致泵的损坏。如果流程系统不需要流量或只需要很少流量，泵保护阀就会自动的将泵所需的最小流量经旁路回流至入口。苏尔达泵保护阀的操作具有可调节性。泵的保护是通过阀门内部元件来自力进行的，工艺系统所需的流量通过旁路回流来自动调节。，当工艺系统需求的流量增加，经旁路的回流便自动减少。反之，亦然。整个系统的效率得以提高，同时工艺流程中不需要增加控制设备，纯机械式操作，使其具有很高的经济性。

（二）功能：

泵保护阀又称自动再循环阀，它集以下四种功能于一体：

（1）流量感知：自动再循环阀能自动感应主流量，以确定主阀瓣的开度； 

（2）再循环控制：自动再循环阀将泵正常运转所需的最小流量旁通到回水箱，防止泵过热；

（3）多级降压：旁路特殊的节流组件，将泵出口介质低噪音、极小磨损地从高压减至系统所需要的压力；

（4）止回功能：自动再循环阀具有止回功能，以防止介质回流到泵内。

泵保护阀主要型号有：SUL系列、TD（含TDL、TDM系列）、TDC型、MRK型、MRM型。

特种控制阀主要包括：蒸汽减温减压阀、背压阀、高压差控制阀、多喷孔套筒调节阀、波纹管控制阀、蒸汽转换阀、一般控制阀等等。

Schroedahl Special Valves GmbH, Germany is a world-renowned specialized valve manufacturer. Particularly in the field of pump protection, it consistently possesses world-leading technology. Since its establishment in 1962, Schroedahl has been dedicated to product R&D, innovation, and the continuous enhancement of manufacturing techniques through the rigorous implementation of strict quality control measures. It has become a global leader in the special valve industry.
For over 60 years, Schroedahl has successively obtained a series of internationally advanced certifications, including AD-HP0 and DIN EN ISO 3834, DGR 97/23/EG, DIN ISO 9001, KTA1401, ISO 14001, and KTA-RWE. To date, it has delivered over 60,000 valves to customers worldwide. The products are widely used in industries and fields such as power generation, steel, energy, chemical, petroleum, natural gas, and offshore drilling platforms, earning high trust and recognition from a broad user base. Our company serves as the representative office of Schroedahl Valves GmbH in China, responsible for sales, technical support, and after-sales service for Schroedahl valves within China.
Schroedahls product line is primarily divided into Pump Protection Valves and Special Control Valves.
Principle and Function of Schroedahl Pump Protection Valves:
(I) Principle:
The function of a pump protection valve is to ensure the minimum flow required by a pump, preventing damage caused by overheating and cavitation. If the process system demands no flow or very little flow, the pump protection valve automatically diverts the necessary minimum flow back to the inlet via a bypass. The operation of Schroedahl pump protection valves is adjustable. Pump protection is achieved through self-actuated internal components, with the bypass flow automatically regulated based on the process systems demand. When the process system requires increased flow, the bypass flow automatically decreases, and vice versa. This enhances overall system efficiency while eliminating the need for additional control equipment in the process. Its purely mechanical operation offers high economic efficiency.
(II) Function:
The pump protection valve, also known as an Automatic Recirculation Control Valve (ARC Valve), integrates the following four functions into one unit:
(1) Flow Sensing: The ARC valve automatically senses the main flow to determine the opening of the main disc.
(2) Recirculation Control: The ARC valve diverts the minimum flow required for normal pump operation to a return tank via a bypass, preventing pump overheating.
(3) Multi-Stage Pressure Reduction: The bypass features special throttling components that reduce the high-pressure pump discharge medium to the system-required pressure with low noise and minimal wear.
(4) Check Function: The ARC valve incorporates a check function to prevent backflow of the medium into the pump.
The main models of pump protection valves include: SUL Series, TD Series (including TDL, TDM Series), TDC Type, MRK Type, MRM Type.
Special Control Valves mainly include: Steam Desuperheating and Pressure Reducing Valves, Back Pressure Valves, High-Pressure Differential Control Valves, Multi-Orifice Sleeve Control Valves, Bellows Seal Control Valves, Steam Switching Valves, General Control Valves, etc.