Slack & Parr

2015

Hydraulic Flow dividers

Slack & Parr is a privately owned UK based company. We were formed in 1917 and we have been involved in the production of high precision gear metering pumps and flow dividers since the late 1940’s.

Slack & Parr Ltd is internationally recognised as a leading designer and manufacturer of high precision geared flow dividers for many industries.

Our pumps are in service worldwide and our customers include some of the most prestigious names in their industries

 

 Company Commitment

 

Towards our Customers

To strive to exceed our customer’s expectation in all we do.

 

Towards our Product

To offer, design, manufacture and support the most suitable, high quality product for our customer’s applications.

 

Towards our employees

To provide a safe working environment and to provide all training opportunities where needed. To continue to provide a steady

new supply of engineers into the company via out credited Apprentice Training Scheme.

What is a flow divider

 

 

A flow divider ensures a controlled and even movement of a number of Hydraulic rams.

Overview

Large capacity (FDL) 2 – 16 outlets subject to pressure drops12 - 30cc/revMaximum pressure 345 bar

 

Small capacity (FDR)

2 – 16 outlets subject to pressure drops

2 - 9cc/rev

Maximum pressure 345 bar

Exploded view of the FDL flow divider

 

 

Exploded view of the FDR flow divider 

Principle of a rotary geared flow divider

Speed of rotation can be as low as 750 rpm and maximum is 3000 rpm, a flow divider should be selected for running between the speeds for maximum efficiency

The rotary gear flow divider consists of two or more gear sections connected along a common shaft. Each section is fed from a common inlet port and has a separate outlet port. Due to the fact that the gear sections are rotating on a common shaft , the rotation speed and hence the fluid displacement is identical for each section. This type of flow division gives a much higher accuracy than spool type flow dividers.

A rotary flow divider has higher accuracy than a spool type as the sliding spool type relies on pressure compensation for accuracy where as the rotary type uses precision ground accurate clearances for efficiency.

 

Principle of a rotary geared flow divider

All flow dividers are supplied with relief valves on each section, which can be used to automatically synchronise multiple cylinders at the end of their stroke. When a cylinder reaches the end of its stroke, the pressure in that section will increase until the relief valve opens, the flow in that section will then be taken through the relief valve and back to tank. The flow in the other sections will continue until they also reach the end of their stroke and the cylinders will now be synchronised.

 

Features of a rotary geared flow divider

Generate an ever improving design of specialised high efficiency geared flow dividers. Our flow dividers are designed and manufactured with particular attention to precision ground surface finishes on gear teeth and plate faces which produce tight clearances giving a much higher efficiency over the competition.

Typical competitor hobbed gear Slack & Parr fully ground gear

 

ISO 9 gear

Ground bore but hobbed gear teeth. Gear

teeth tolerance – 0.002”

ISO 5 gear

Ground faces, bore and gear teeth. Gear

teeth tolerance – 0.0005”

Features of rotary geared flow dividers

Rotary flow dividers meter the inlet flow from a single supply into 2 or more output of equal or unequal flows

 

Features of rotary geared flow dividersThe two ranges of flow divider is of modular construction and interchangeable parts. A number of stages can provide very large flow ranges.

 

 

ORDERINGCODE

No. OFOUTLETS

MINIMUMINLET

MAXIMUMINLET

    GALLONS/MIN. GALLONS/MIN.       

FDR 2/2FDL 2/30 2 0.8

11.93.2

47.6       

FDR 3/2FDL 3/30 3 1.2

17.84.8

71.3       

FDR 4/2FDL 4/30 4 1.6

23.86.3

95.1

       

FDR 5/2FDL 5/30 5 2

29.78

118.9       

FDR 6/2FDL 6/30 6 2.4

35.79.5

142.7

Typical applications for a rotary geared flow divider

Lifting arms (Davit technology) – Welin LambiePipe/Drill clamping in the Oil industry - WeatherfordHydraulic press/stamping – Pegler plumbing fittingsAgricultural machinery – Larrington trailers/Hoof trimming Railroad track laying – Network rail (UK)Waste compactors – Axis HydraulicsLubrication systems – Tunnel boring systems – Herrenknecht Sub sea machinery – Pipe laying platforms – Subsea InnovationsSteel mills – movement of steel ingots/furnace doors – Tata SteelTriple deck car transporter trailers - Transporter engineering

 

Important features

• Precision flow dividers for high accuracy .

• Interchangeable with many existing Installations with standard SAE & ISO fittings

• Gears manufactured from fully hardened AISI 440B material for long life .

• Stainless steel material combinations are available on request

• Full technical support and repair facilities in:

• UK

• North Carolina USA

• China

Gear grinding

Lapping operation

Key manufacture processes

Gear CMM Inspection

Full testing facilities

Key manufacture processes

Any questions?