Type Alfa-P

Belt-drive couplings supplied with or without pulley (Alfa-P) — constant-fill, fixed-speed power transmission with soft starting built in.

Description

Constant-fill power, designed for belt drives.

Fluidomat Type Alfa-P is a constant-fill, fixed-speed fluid coupling built for belt-drive applications. It is offered in different executions — with or without a delay-fill chamber — to match the starting characteristics of the driven machine.

Alfa-P couplings can be supplied without a pulley: within the specified range, the buyer can manufacture and fit the pulley at their own end. This gives real flexibility for stocking, and lets pulleys of different specification run on the same coupling.

Each coupling is suitable for two consecutive starts from hot and three from cold. A fusible plug provides thermal protection, blowing off at 130°C as standard (160°C optional). The recommended lubricant is Turbine Oil ISO VG 32.

Fluidomat Type Alfa-P belt-drive coupling

Key data

85
KW max rating (model 7 @ 1800 RPM)
2–5%
Operating slip
130°C
Fusible plug blow-off (std)
3
Executions: P / PD / PDX
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Specification

Built-in features of every Alfa-P coupling

  • Belt-drive configuration in P, PD and PDX executions — with or without a delay-fill chamber to suit the load
  • Supplied with or without pulley; pulleys within the tabulated range can be made and installed by the buyer
  • Flexible stocking — pulleys of different specification can run on the same coupling
  • Rated for two consecutive starts from hot and three from cold
  • Fusible plug blow-off temperature 130°C as standard, 160°C optional
  • Operating lubricant: Turbine Oil ISO VG 32
  • Smooth, soft starting that limits torque and absorbs shock loads and torsional vibration
  • Five frame sizes (models 3 to 7) covering belt-driven duties up to 85 KW
Selection data

Rating table — Alfa-P / PD / PDX

Maximum ratings in KW at different input speeds (RPM). For final selection, please consult Fluidomat application engineering.

Maximum rating (KW) by input speed — Type Alfa-P / PD / PDX
Model600730900970120014701800
3—1.32.4361118
41245916.522
5247916.33042
635911224060
7481518346285

Full dimension tables, pulley details, dry weights and oil quantities for the P, PD and PDX executions are available in the Alfa-P catalogue.

Selection data

Specifications

Pitch-circle diameters, overall and mounting dimensions (mm), dry weight (kg) and maximum oil filling (litres) for the P, PD and PDX executions.

Alfa-P / PD / PDX — technical specification & dimensions (mm), dry weight (kg) and oil filling (ℓ)
ModelPCD D3PCD D4ØDØAB — PB — PDB — PDXØd1 maxℓ1Dry wt PDry wt PDDry wt PDXOil POil PDOil PDXThreads M
317512065342289351390421102427282.83.23.23/4"
417512075367292361390501103034353.84.24.23/4"
521514090406356413463651424044454.95.45.41"
6255162100435395456526651425559615.67.17.11"
7255162110471405464534751426671738.38.88.81 1/2"

All dimensions in mm. B is given for each execution (P / PD / PDX). Dry weight in kg; maximum oil filling in litres (ℓ). Threads ‘M’ to BSW.

Pulley mounting details

Pulley locating diameter, mounting PCD, radial offset ‘R’ and coupling tapping data (N / J / M) by frame size.

Alfa-P / PD / PDX — pulley locating diameter, mounting PCD, ‘R’ offset and N / J / M holes
ModelLocating dia D5 (Type 1, 2 & 3)Locating dia D6 (Type 4)PCD D3PCD D4R (Type 1 & 2)R (Type 3)R (Type 4)NJM on coupling
3145207175120455810M10
4145207175120455810M10
5180255215140575810M10
6220295255162575810M10
7220295255162575810M10

‘N’ — number of holes; ‘J’ — diameter of drilled holes for ‘M’ — tapped hole in coupling. All dimensions in mm.

Pulley details — Type 1

Groove section, “D” pitch-circle diameter range, number of grooves and ‘K1’ offset.

Pulley Type 1 — groove data by frame size
ModelSec.“D” PCD min Ø“D” PCD max ØNo. off grooveK1
Alfa P/PD/PDX 3 & 4BØ115Ø14547.3
Alfa P/PD/PDX 3 & 4CØ120Ø14035
Alfa P/PD/PDX 3 & 4SPAØ115Ø14558.5
Alfa P/PD/PDX 3 & 4SPBØ120Ø14547.3
Alfa P/PD/PDX 3 & 4SPCØ130Ø14035
Alfa P/PD/PDX 5BØ130Ø180610.6
Alfa P/PD/PDX 5CØ140Ø180420.9
Alfa P/PD/PDX 5SPAØ130Ø180719
Alfa P/PD/PDX 5SPBØ135Ø180610.6
Alfa P/PD/PDX 5SPCØ145Ø180420.9
Alfa P/PD/PDX 6 & 7BØ150Ø220716.3
Alfa P/PD/PDX 6 & 7CØ160Ø220520.6
Alfa P/PD/PDX 6 & 7SPAØ150Ø220914.5
Alfa P/PD/PDX 6 & 7SPBØ160Ø220716.3
Alfa P/PD/PDX 6 & 7SPCØ170Ø220520.6

Pulley details — Type 2

Groove section, “D” pitch-circle diameter range, number of grooves and ‘K1’ / ‘K2’ offsets. Type 2 is not available on frame sizes 6 & 7.

Pulley Type 2 — groove data by frame size
ModelSec.“D” PCD min Ø“D” PCD max ØNo. off grooveK1K2
Alfa P/PD/PDX 3 & 4BØ145Ø17221533.5
Alfa P/PD/PDX 3 & 4CØ140Ø1802133.5
Alfa P/PD/PDX 3 & 4SPAØ145Ø1723933.5
Alfa P/PD/PDX 3 & 4SPBØ140Ø18021533.5
Alfa P/PD/PDX 3 & 4SPCØ140Ø1402133.5
Alfa P/PD/PDX 5BØ180Ø20041839
Alfa P/PD/PDX 5CØ180Ø210316.539
Alfa P/PD/PDX 5SPAØ180Ø20054.539
Alfa P/PD/PDX 5SPBØ180Ø21041839
Alfa P/PD/PDX 5SPCØ180Ø220316.539
Alfa P/PD/PDX 6 & 7B—————
Alfa P/PD/PDX 6 & 7C—————
Alfa P/PD/PDX 6 & 7SPA—————
Alfa P/PD/PDX 6 & 7SPB—————
Alfa P/PD/PDX 6 & 7SPC—————

Pulley details — Type 3

Groove section, “D” pitch-circle diameter range, number of grooves and ‘K1’ offset.

Pulley Type 3 — groove data by frame size
ModelSec.“D” PCD min Ø“D” PCD max ØNo. off grooveK1
Alfa P/PD/PDX 3 & 4BØ172Ø230417.3
Alfa P/PD/PDX 3 & 4CØ180Ø235315
Alfa P/PD/PDX 3 & 4SPAØ172Ø230518.5
Alfa P/PD/PDX 3 & 4SPBØ180Ø235417.3
Alfa P/PD/PDX 3 & 4SPCØ190Ø245315
Alfa P/PD/PDX 5BØ200Ø27075
Alfa P/PD/PDX 5CØ210Ø27059.3
Alfa P/PD/PDX 5SPAØ200Ø270818
Alfa P/PD/PDX 5SPBØ210Ø27075
Alfa P/PD/PDX 5SPCØ220Ø27059.3
Alfa P/PD/PDX 6 & 7BØ225Ø320811.3
Alfa P/PD/PDX 6 & 7CØ225Ø32069.15
Alfa P/PD/PDX 6 & 7SPAØ225Ø3201013.5
Alfa P/PD/PDX 6 & 7SPBØ225Ø320811.3
Alfa P/PD/PDX 6 & 7SPCØ235Ø40069.15

Pulley details — Type 4

Groove section, “D” pitch-circle diameter range, number of grooves and ‘K1’ offset.

Pulley Type 4 — groove data by frame size
ModelSec.“D” PCD min Ø“D” PCD max ØNo. off grooveK1
Alfa P/PD/PDX 3 & 4BØ235Ø320422
Alfa P/PD/PDX 3 & 4CØ240Ø320320.6
Alfa P/PD/PDX 3 & 4SPAØ235Ø320523.5
Alfa P/PD/PDX 3 & 4SPBØ240Ø320422
Alfa P/PD/PDX 3 & 4SPCØ250Ø320320.6
Alfa P/PD/PDX 5BØ275Ø350710
Alfa P/PD/PDX 5CØ285Ø350514.3
Alfa P/PD/PDX 5SPAØ280Ø350823.3
Alfa P/PD/PDX 5SPBØ285Ø350710
Alfa P/PD/PDX 5SPCØ295Ø350514.3
Alfa P/PD/PDX 6 & 7BØ325Ø400814.3
Alfa P/PD/PDX 6 & 7CØ325Ø400616.3
Alfa P/PD/PDX 6 & 7SPAØ325Ø4001014.15
Alfa P/PD/PDX 6 & 7SPBØ325Ø400816.3
Alfa P/PD/PDX 6 & 7SPCØ335Ø400614.3

All pulley diameters and offsets in mm. Groove sections to BS / DIN V-belt standards; other sections can be provided on request. For final pulley selection consult Fluidomat application engineering.

Construction & diagrams

Diagrams & views

Fluidomat Type HD-P
Fluidomat Type HD-P
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Fluidomat Type HD-P
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Fluidomat Type HD-P
Typical applications

Proven across belt-driven equipment

Belt conveyors Crushers Fans & blowers Centrifugal pumps Compressors Mixers & agitators Screens & feeders Material handling
Constant-Fill CouplingsFixed-speed soft-start range Variable Speed Scoop (SC)Energy-saving stepless control Catalogues & downloadsDimension & selection data

Need an Alfa-P coupling for your belt drive?

Send us your motor rating, speed and pulley details and our engineers will help you select the right Alfa-P coupling.

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