Parallel Spring and Conical Spring Configurations

The Luwint MT560D range provides double mechanical seal configurations for submersible pump repair, subject to matching the original assembly. The catalogue identifies an inboard impeller side and an outboard lubricant side, with parallel spring and conical spring versions to suit different shaft and stationary-seat arrangements.

Replacing a submersible pump seal requires more than a matching shaft diameter. Both ends of the assembly, the stationary-seat housings and the installed working length need to be checked. MT560D selection starts with these details so the replacement can be assessed against the pump being serviced.

Why Choose the MT560D Range

• Two spring configurations: parallel spring versions for equal shaft diameters at both ends, and conical spring versions with different inboard and outboard shaft diameters.

• Multiple stationary-seat arrangements: cup-mounted, vulcanised and O-ring-mounted options are listed across the range, depending on configuration.

• Separate dimensions for each end: the catalogue identifies the impeller-side and lubricant-side requirements individually, helping distinguish assemblies that look similar.

• Help with replacement selection: send the old seal dimensions and pump details for assessment before ordering.

Choosing the Correct Configuration

Configuration	Catalogue shaft sizes	Key selection point
Parallel spring	Selected sizes from 12 to 70 mm	Equal shaft diameter at both ends; seat type and housing bore can differ between ends.
Conical spring	Inboard/outboard pairs: 25/30, 30/35, 35/40, 40/45 and 45/50 mm	Match both shaft diameters, spring arrangement and stationary seats.

Dimensions are in millimetres. Catalogue coverage does not indicate current stock availability.

For example, the parallel spring table lists two 20 mm configurations with different inboard housing bores: 38 mm and 44 mm. Both list a 38 mm outboard bore. Ordering simply a “20 mm double seal” would leave this difference unresolved.

Confirm the complete installed working length as well as both seat dimensions. The overall appearance or free length of a removed spring is not sufficient to establish fit.

Submersible Pump Applications in Australia

Japanese pump manufacturers use double mechanical seals in submersible drainage and sewage pump designs. Ebara's DS range is one example; Tsurumi also describes dedicated oil-chamber lubrication for its submersible pump mechanical seals. These arrangements help explain why both sealing ends and the lubricant-side conditions matter during repair.

Subject to verified dimensions, materials and duty, MT560D configurations can be considered for:

• Sump and building drainage pump repairs

• Wastewater and sewage transfer pump maintenance

• Site dewatering and stormwater pump servicing

These are application categories for selection, not a list of confirmed pump models. An Ebara or Tsurumi nameplate alone does not establish MT560D compatibility. Supply the complete pump model and original seal details for checking.

Materials and Operating Conditions

Confirm the face and stationary-seat materials, elastomer and metal specification for the selected assembly. Selection must account for the pumped liquid, suspended solids, lubricant, temperature, pressure and shaft speed.

Ask Luwint to confirm the applicable operating limits and material combination for your configuration before ordering.

Sydney Supply. Help with Selection.

Contact Luwint for current availability, pricing and dispatch timing for your required configuration.

Please send the pump make and model, both shaft diameters where applicable, stationary-seat housing diameters and depths, installed working length, and clear photographs of both ends of the old seal. Include the liquid, lubricant and operating conditions.

Ask for the full catalogue and the dimensional drawing for the configuration being considered.

Contact: Wayne Liao
Email: wayne@luwintonline.com
Mobile: 0433 986 633

LUWINT supplies aftermarket replacement products and is independent of Ebara and Tsurumi. Brand names are used for identification and application context only; they do not imply affiliation, endorsement or confirmed interchangeability.