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| 1. Gather your application data first. Following data is important. |
Fluid to be pumped and its physical and chemical
characteristics
Viscosity
pH value
Specific Gravity
Size of suspended solids, if any
Discharge rate required
Head at which discharge is required
Suction head if any
Pipe line diameter intended/existing and no. of bends |
| 2. Select the diaphragm, ball and seat material. STROKE pumps offers the following material choices |
| Neoprene |
| An excellent general purpose diaphragm for use in non-aggressive applications such as water-based slurries, well water or sea water. Exhibits excellent flex life and low cost. Temperature range -18°Cto +93°C (O°Fto +200°F) |
| Buna N |
| Excellent for applications involving petroleum / oil-based fluids such as leaded gasolines, fuel oils, non-synthetic hydraulic oils, kerosene, turpentine and motor oils. Temperature range -12°C to -i-82°C (+10°F to + 180°F) |
| Viton |
Excellent for use in applications requiring extremely hot
temperatures. May also be used with aggressive fluids such
as aromatic or chlorinated hydrocarbons and highly
aggressive acids. Especially where high suction lift is
important.
Temperature range -40°C to -175°C (-40°F to +350°F) |
| Teflon |
| Excellent choice when pumping highly aggressive fluids such as aromatic or chlorinated hydrocarbons, acids, caustics, ketones and acetates. Temperature range +4°C to +104°C (+40°F to +220°F) |
| Santoprene |
Exhibits excellent abrasion resistance, flex life and durability.
Excellent general purpose diaphragm.
Temperature range -40°C to +107°C (-40°F to +225°F) |
| 3. Once the diaphragm, ball and seat material is chosen, select the correct material of construction of the pump. STROKE Pumps offers following material of construction choices: |
| Cast Iron |
| Good for fluids having pH between 3.5 and 5.5 (acidic) and between 8.5 to 10.5 (alkaline) |
| Aluminium |
| Good for fluids having pH between 5.5 and 8,5 |
| Stainless Steel |
| Good for stronger concentrated acids and alkaline |
| Polypropylene |
| Good alternative low cost choice where fluid is compatible especially chemical compatibility and temperatures. Polypropylene is good between temperature ranges of +12° to+107°Cand +32° to+175°F. |
| PVDF |
| Exhibits a higher temperature range of -12° to +107°C and -10° to+225°F. |
| 4. Establish TOTAL head |
Now establish the TOTAL Head using the below
calculation.
TOTAL Head = Specific gravity X (Suction Head +
Discharge head) + approx Additional head (due to pipe
bends). Roughly about 10 feet for each 90° Bend.
Finally check that the selected pump meets the below
guidelines for viscous fluids. |
| 5. Establish Pump Model most suited |
| Every STROKE pump technical specifications include the pump flow curves. Looking at the pump flow curves, establish the point where the TOTAL Head and required discharge intersect. This intersection pump should ideally be somewhere in the middle of the graph. That is the pump should achieve the required discharge @Head at the supply air pressure of about 70 PSI. With STROKE Diaphragm pumps you only consume as much air as is needed to move the fluid, irrespective of pump size, so it is beneficial to select a pump whose daily operation will be in the middle of the pump performance. |
| The STROKE flow curves are all based on pumping of water. When pumping viscous fluids pump output reduces according to the graph. Be sure to compensate for viscous fluids. |
| 6. Check Solids Handling Capability |
| Maximum slurry particle size must not be greater than the pump's solids passage capability. A strainer may be placed on the inlet line to eliminate particles larger than the pump's capability. Please refer to individual specifications for you pump's specific solids passage capabilities. |
