Send a part number, a photo, or a whole BOM — we supply it and stand behind it. Worldwide shipping to 80+ countries.

3G Electric
RFQ CartGet a QuoteSign inSign up

MCDONNELL

McDonnell & Miller, a brand under ITT Inc., has been a manufacturer of fluid control and safety devices for boiler and HVAC systems since its founding in the early 20th century. The brand is recognized for its line of level controls, flow switches, relief valves, and related components used in steam and hot water systems. 3G Electric supplies a range of McDonnell & Miller replacement parts, including electrical switches, sensors, strainer baskets, head mechanisms, cartridge kits, level controls, and valve assemblies. These components are designed for use in commercial and industrial heating, ventilation, air conditioning, and refrigeration (HVACR) applications, particularly in systems requiring precise monitoring of water levels, flow rates, and pressure. The product line includes manual reset switches like the 7-BM, multi-level sensors such as the RS-4-BR-1, and strainer basket assemblies like the 340700, all built to meet industry standards for durability and reliability in demanding environments. McDonnell & Miller components typically feature brass or steel construction, with IP ratings suitable for indoor boiler room installations, and are rated for pressures up to 150 psi and temperatures up to 250°F depending on the model. 3G Electric stocks over 116 SKUs of McDonnell & Miller products, offering global logistics support to ensure availability for maintenance, repair, and operations (MRO) needs. The catalog includes both OEM and replacement parts, with compatibility information provided for each SKU to assist engineers and procurement specialists in selecting the correct component for existing systems. By maintaining a comprehensive inventory, 3G Electric enables plant engineers and maintenance managers to source critical spares for boiler feedwater controls, condensate return systems, and HVACR pump assemblies without extended lead times.

Genuine
OEM Parts
Expert
Tech Support
1 Day
Quote Response
Worldwide
Origin
Worldwide Shipping
Air & sea freight
Datasheets on Request
Technical specs & drawings
1-Day Quote Response
Singapore-based team
Show
Page 5 of 12

About MCDONNELL

McDonnell & Miller, a brand under ITT Inc., has been a manufacturer of fluid control and safety devices for boiler and HVAC systems since its founding in the early 20th century. The brand is recognized for its line of level controls, flow switches, relief valves, and related components used in steam and hot water systems. 3G Electric supplies a range of McDonnell & Miller replacement parts, including electrical switches, sensors, strainer baskets, head mechanisms, cartridge kits, level controls, and valve assemblies. These components are designed for use in commercial and industrial heating, ventilation, air conditioning, and refrigeration (HVACR) applications, particularly in systems requiring precise monitoring of water levels, flow rates, and pressure. The product line includes manual reset switches like the 7-BM, multi-level sensors such as the RS-4-BR-1, and strainer basket assemblies like the 340700, all built to meet industry standards for durability and reliability in demanding environments. McDonnell & Miller components typically feature brass or steel construction, with IP ratings suitable for indoor boiler room installations, and are rated for pressures up to 150 psi and temperatures up to 250°F depending on the model. 3G Electric stocks over 116 SKUs of McDonnell & Miller products, offering global logistics support to ensure availability for maintenance, repair, and operations (MRO) needs. The catalog includes both OEM and replacement parts, with compatibility information provided for each SKU to assist engineers and procurement specialists in selecting the correct component for existing systems. By maintaining a comprehensive inventory, 3G Electric enables plant engineers and maintenance managers to source critical spares for boiler feedwater controls, condensate return systems, and HVACR pump assemblies without extended lead times.

Common Applications

  • Steam boiler low-water cutoff — McDonnell & Miller 61 level control
  • Condensate receiver level monitoring — McDonnell & Miller RS-4-BR-1 4-level sensor
  • HVACR pump suction filtration — McDonnell & Miller 340700 strainer basket assembly
  • Flow switch head replacement — McDonnell & Miller 63-HD head mechanism
  • Boiler control circuit safety — McDonnell & Miller 7-BM electrical switch with manual reset
  • Field servicing of flow switches — McDonnell & Miller 310452 cartridge kit

Frequently asked questions

Common questions about MCDONNELL from 3G Electric.

What is the function of the McDonnell & Miller 7-BM electrical switch with manual reset?

The McDonnell & Miller 7-BM is an electrical switch with manual reset, typically used in boiler control circuits to interrupt power when a fault condition occurs, such as low water level or excessive pressure. The manual reset feature requires an operator to physically reset the switch after the fault is cleared, ensuring that the system is inspected before restarting. It is compatible with part number 110900 and is commonly applied in steam and hot water heating systems.

How does the McDonnell & Miller RS-4-BR-1 4-level sensor work in HVACR systems?

The RS-4-BR-1 is a 4-level sensor that detects liquid levels at four distinct points within a tank or vessel. It uses a float mechanism or conductivity probes to signal when levels reach preset thresholds, enabling control of pumps, alarms, or valves. This sensor is compatible with part number 179527 and is used in condensate receivers, boiler feedwater tanks, and other HVACR applications requiring multi-point level monitoring.

What is the purpose of the McDonnell & Miller 340700 strainer basket assembly?

The 340700 strainer basket assembly is a replacement component designed to filter debris from fluid flow in HVACR pump systems. It captures particles that could damage downstream equipment, such as valves or heat exchangers. Compatible with part number 342200, this strainer basket is typically installed in the suction line of pumps to maintain system efficiency and prevent clogging.

Can the McDonnell & Miller 63-HD head mechanism be used as a direct replacement for the MM-701F?

Yes, the 63-HD head mechanism is designed as a replacement for the MM-701F assembly. It includes the internal components necessary to restore the function of a flow switch or level control device. The head mechanism houses the switching element and actuation linkage, and it is compatible with the same mounting and piping configurations as the original MM-701F.

What does the McDonnell & Miller 310452 cartridge kit include?

The 310452 cartridge kit contains replacement internal components for a McDonnell & Miller flow switch or level control device. It typically includes a diaphragm, spring, and sealing elements that restore the device's sensitivity and sealing integrity. Compatible with part number 342500, this kit is used for field servicing to extend the life of existing controls without replacing the entire assembly.

How is the McDonnell & Miller 61 level control typically installed?

The McDonnell & Miller 61 level control is a float-operated device installed directly into a boiler or tank through a threaded or flanged connection. It monitors water level and actuates electrical contacts to control feedwater pumps or alarms. The 61 model is designed for low-water cutoff applications in steam boilers and is wired into the burner control circuit to prevent operation when water level is insufficient.