How do I calculate Total Dynamic Head (TDH) for pump selection?

TDH is calculated using the formula: TDH = Vertical Lift + Friction Loss + Required Outlet Pressure. Vertical lift is the height between water source and highest outlet. Friction loss is resistance from pipe length, diameter, and bends (use friction loss tables or calculators). Required outlet pressure is the pressure needed at taps or sprinklers (typically 2.5-3.5 bar or 25-35m for residential). Example: Borehole 40m deep + 200m horizontal pipe with 18m friction loss + 25m sprinkler pressure = 83m TDH total. This TDH value must be matched with your flow requirement using pump performance curves.

What flow rate do I need for my home?

Flow rate depends on home size and simultaneous usage: 1 Bed, 1 Bath needs 20-30 L/min at 2.0-2.5 bar (25-30m head). 3 Bed, 1 Bath needs 40-50 L/min at 2.5 bar (30-35m). 3 Bed, 2 Bath with garden needs 50-70 L/min at 3.0 bar (35-45m). Large home with irrigation needs 80-120 L/min at 3.5-4.0 bar (50-60m). Calculate by adding simultaneous outlets: showers (10-12 L/min each), taps (10-15 L/min each), sprinklers (15-25 L/min each). Only count outlets that will operate at the same time during peak usage.

How do I use pump performance curves to select the right pump?

Pump performance curves show pressure (head in metres) versus flow rate (L/min). First, calculate your operating point: your required flow rate and your calculated TDH. Find where these two values intersect on the graph. Select a pump whose performance curve passes through or slightly above your operating point. Never size based on maximum head or maximum flow shown on the curve - these occur at zero flow and zero head respectively. Your pump must deliver your required flow at your required head simultaneously. Don't size pump on power alone - a higher power pump is not automatically better if its curve doesn't match your operating point.

What is the difference between peripheral and centrifugal pumps?

Peripheral vane pumps generate high pressure from compact size, making them ideal for domestic pressure boosting where high head is needed with moderate flow. They are self-priming and excel at applications like geyser boosting and tap pressure improvement. Centrifugal pumps move larger volumes at moderate pressure, making them better for high flow applications like garden irrigation and tank transfer. They handle continuous duty well and are robust for long horizontal pipe runs. Centrifugal pumps are not self-priming and require foot valve or manual priming. Choose peripheral for pressure boosting, centrifugal for high flow irrigation and transfer.

Can I install a surface pump to lift water from a borehole?

Surface pumps have limited suction capability, typically maximum 7-8 metres vertical lift on the suction side. If your borehole water level is deeper than 7-8m below ground, a surface pump cannot lift the water - you must use a submersible borehole pump. Surface pumps can push water upward on the discharge side with no limit (up to their pressure rating), but they cannot create sufficient vacuum to suck water up from deep sources. For shallow wells and tanks within 7-8m suction lift, surface pumps work well. For deeper boreholes, submersible pumps are the only option as they push water upward from depth.

Why won't my surface pump hold prime overnight?

Surface pumps lose prime overnight due to leaky foot valve or non-return valve on the suction side. The foot valve or NRV must seal perfectly to prevent water draining back to source when pump stops. Common causes: worn valve flap or seat, debris preventing valve closure, damaged valve body, or no foot valve installed at all. Solution: Install a quality foot valve at end of suction pipe in the water. If valve exists, remove and inspect for damage or debris. Replace if worn. Also check all suction pipe connections for air leaks that could break the water column. Even tiny air leaks prevent maintaining prime.

What size pipe should I use to reduce friction loss?

Pipe diameter significantly affects friction loss - larger pipes have dramatically lower friction. As rough guide: 25mm (1 inch) pipe at 60 L/min loses about 10m head per 100m length. 32mm (1.25 inch) pipe at same flow loses only about 3m per 100m length - more than 3 times less friction. 40mm (1.5 inch) pipe loses even less. For long runs or high flow rates, always upsize pipe diameter to reduce friction loss. The extra cost of larger pipe is quickly recovered in reduced pump size, power consumption, and better performance. Each 90-degree elbow adds equivalent of 1-2m of straight pipe friction. Minimize bends where possible.

What happens if I oversize my pump?

Oversizing slightly (10-20%) is acceptable and provides safety margin. However, significant oversizing causes: short cycling (pump starts and stops rapidly) which reduces lifespan, increased energy consumption and higher operating costs, excessive pressure requiring pressure reducing valves, potential water hammer from rapid flow changes, and inefficient operation as pump runs far from its optimal efficiency point. Slight oversizing is safer than undersizing, but never oversize too much. If pump delivers much more pressure than needed, it will cycle on pressure switch too frequently, wearing mechanical and electrical components prematurely.

How do I troubleshoot weak water pressure from my pump?

Weak pressure troubleshooting depends on pump type. For peripheral pumps: check for airlock in pump body (re-prime), dirty impeller (dismantle and clean), or no non-return valve (install NRV on suction). For centrifugal pumps: check for undersized pipe causing friction loss (upsize pipe), impeller blockage (clean pump), or air in system (bleed air and check for leaks). For multistage pumps: air in system (bleed air and check for blockages) or controller fault (inspect or replace controller). For all types: verify system TDH hasn't exceeded pump rating, check for pipe restrictions or blockages, confirm pump is operating at correct voltage, and ensure impeller hasn't worn from age.

Why does my submersible pump trip the circuit breaker?

Submersible pump tripping indicates: cable damage allowing water ingress and short circuit (test cable insulation resistance, replace damaged cable), electrical overload from undersized wiring (check wire gauge matches pump current requirement and cable length), motor failure or seized bearing (test motor winding resistance), incorrect voltage causing overcurrent (verify supply voltage matches pump rating), or pump running against blocked outlet creating excessive load (check for closed valves or blockages). If cable is damaged, water enters and causes intermittent or permanent short circuit. Always support pump on rope, never on power cable, to prevent cable damage.

Can I run a regular AC pump with solar panels?

No, you cannot run AC (alternating current) pumps directly from solar panels without proper inverter system. Solar panels produce DC (direct current) electricity. Running AC pumps from solar requires: solar charge controller, battery bank for storage, and inverter to convert DC to AC. This system is expensive and inefficient due to multiple conversion losses. Instead, use dedicated solar DC pumps designed for direct solar operation. Solar DC pumps connect directly to solar panels through MPPT controller, eliminating batteries and inverters for much more efficient, reliable, and cost-effective off-grid pumping. Choose DC voltage pump (24V, 48V, or 72V) matching your solar panel array configuration.

What voltage solar pump do I need?

Solar pump voltage selection depends on power requirement and head: 24V DC pumps (up to 250W) suit small off-grid water transfer, shallow boreholes, and livestock watering with 2×150W panels. 48V DC pumps (up to 500W) suit medium borehole supply and modest irrigation with 4×150W panels. 72V DC pumps (up to 750W) suit deep boreholes, high lift applications, and long-distance delivery with 6×150W panels. Higher voltage allows more efficient power transmission through cables and better performance at high head applications. Match panel array voltage to pump voltage by connecting panels in series: four 12V panels in series = 48V, six 12V panels in series = 72V.

Why does my pump cavitate and make noise?

Cavitation occurs when pump creates low pressure zones where water vaporizes, forming bubbles that collapse violently, causing noise and damage. Causes for surface pumps: excessive suction lift (pump trying to lift water from too deep), suction pipe restrictions or undersizing (not enough water reaching pump), air leaks in suction line (allowing air ingress), or pump running too fast for application. For submersible pumps: pump not fully submerged (sucking air), running dry, or clogged intake screen restricting flow. Solutions: reduce suction lift, increase suction pipe diameter, check for and repair air leaks, ensure pump fully submerged, clean intake screen, verify pump sizing correct for application. Cavitation damage is cumulative and destroys impellers and housings over time.

What is the purpose of a non-return valve (NRV)?

Non-return valves (NRV) or check valves serve critical functions: On suction side of surface pumps, they maintain prime by preventing water draining back to source when pump stops - without NRV pump loses prime overnight. On discharge side before controllers, they protect pressure switches and controllers from backflow damage. For borehole systems, they prevent water column draining back down borehole between pump cycles, reducing startup load and water waste. NRVs must be installed correctly: vertical mounting with flow arrow pointing in pumping direction. Quality NRVs with spring-loaded flap close reliably. Cheap NRVs with gravity-only closure often fail to seal, causing prime loss and system problems.

How do I know if my pump is the wrong size?

Signs of incorrect pump sizing: Undersized pump: weak pressure at outlets, pump runs continuously, cannot supply all outlets simultaneously, excessive motor temperature from overload, pump struggles to start or trips breaker. Oversized pump: short cycling (rapid on-off), excessive pressure requiring pressure reducer, water hammer from fast flow changes, high electricity bills, pressure switch cycles too frequently. Correctly sized pump: delivers adequate pressure at all outlets, runs for reasonable cycles (not constant, not rapid cycling), operates quietly without strain, starts reliably, and provides consistent performance across usage range. If experiencing problems, verify pump's operating point on performance curve matches your calculated flow and TDH requirements.

What is friction loss and why does it matter?

Friction loss is pressure drop caused by water resistance flowing through pipes, fittings, and valves. It matters because friction loss directly reduces available pressure at outlets - pressure pump generates must overcome both vertical lift and friction loss before any remains for outlet pressure. Friction depends on: pipe diameter (smaller = much higher friction), pipe length (friction is cumulative), flow rate (friction increases exponentially with flow), pipe roughness (smooth pipes have less friction), and number of fittings and bends (each adds resistance). Ignoring friction loss leads to undersized pumps delivering poor pressure. For long pipe runs, friction loss can exceed vertical lift as the dominant factor. Always calculate friction loss when sizing pumps.

Why does my dirty water pump keep clogging?

Dirty water pump clogging indicates wrong pump type for application. Standard impeller pumps clog on solids and stringy materials. Solution: use vortex impeller pumps specifically designed for dirty water. Vortex impellers create spinning flow that passes solids through pump without clogging - they have recessed impeller with open channel. For sewage and heavily contaminated water, use sewage pumps rated for solids passage (check specification for maximum solids size). Standard clean water submersibles have tight impeller clearances and will clog immediately in dirty water. Also ensure: pump intake not sitting on bottom sucking sludge, float switch positioned above sludge layer, and regular inspection/cleaning of intake screen if equipped.

What electrical protection do I need for my pump?

Essential electrical protections: Earth leakage protection (RCD or ELCB) to prevent electrocution if pump develops earth fault, correctly sized circuit breaker matching pump current draw (check pump nameplate for current), proper wire gauge for pump power and cable run length (undersized wire causes voltage drop and overheating), overload relay for motor protection against overcurrent, and for submersibles: watertight cable joints using heat-shrink or resin-filled kits. Always use certified electrician for pump electrical installations. Verify supply voltage and frequency match pump rating exactly. For single-phase pumps on three-phase supply, use proper isolation. For control systems, use contactors rated for pump starting current (5-8 times running current).

How do I calculate friction loss in my pipe system?

Calculate friction loss using friction loss tables or online calculators that account for pipe diameter, flow rate, and pipe length. Method: determine your flow rate (L/min), measure total pipe length including all horizontal and vertical runs, identify pipe diameter, look up friction loss per 100m from table for your flow and pipe size, multiply by your total pipe length divided by 100. Add equivalent length for fittings: each 90-degree elbow adds 1-2m, each valve adds 3-5m, each T-junction adds 2-3m. Example: 200m of 32mm pipe at 60 L/min with 10 elbows = (200×0.09) + (10×1.5) = 18 + 15 = 33m friction loss total. This is why larger pipes matter - 40mm pipe at same flow might have only 10m friction loss.

Why won't my float switch turn off my pump automatically?

Float switch auto-cutoff failure causes: float tangled or snagged on pump, pipes, or tank walls (ensure free movement), float switch logic wired incorrectly - NO (normally open) and NC (normally closed) terminals reversed (verify wiring matches system requirements), float damaged or waterlogged (test float buoyancy), float cable too short restricting travel (provide adequate cable length), or controller/relay failure (test electrical operation). For tank applications, position float where it can travel full range without obstruction. Mount pump away from tank walls. Secure float cable to prevent wrapping around pump or pipes. Test float operation during installation by manually raising and lowering to verify pump starts and stops correctly.

TAIFU Pump Selection and Training

2025-07-02 09:03:41

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TAIFU Pump Selection Simplified: Technical Training Meets Practical Setup

Choosing the right pump isn't just about power, it's about matching pressure, flow rate, and water source conditions to the right product. With TAIFU, you’re backed by decades of hydraulic experience and a range tailored to South Africa’s residential, agricultural, and commercial demands.

MAC AFRIC SP400 Submersible Water Pump with Float Switch

MAC AFRIC SP750W Submersible Pump with Float Switch

TAIFU Submersible Sewage Pump 0.55 kW WFD6-12-0.55A

TAIFU 2” Bore Hole Pump 0.25 kW 2STM1-30

TAIFU Submersible Pressure Pump 0.75 kW QDX1.5-32-0.75LA

TAIFU Submersible Pressure Pump 0.37 kW QDX1.5-17-0.37LA

TAIFU SGJ600 Stainless Steel Pressure Pump 0.6 kW

TAIFU SGJ800 Stainless Steel Pressure Pump 0.8 kW

TAIFU 3” Solar DC Bore Hole Pump 250W 24V DC

TAIFU 3” Solar DC Bore Hole Pump 500W 48V DC

TAIFU TCP200 Centrifugal Pressure Pump 1.5 kW

TAIFU Circulating Pump 245W GRS15-11-Z

TAIFU QB60 Peripheral Vane Pressure Pump 0.37 kW

TAIFU 4” Bore Hole Pump 0.75 kW 4STM4-10

TAIFU 4” Bore Hole Pump 1.1 kW 4STM4-14

TAIFU 3” Bore Hole Pump 0.37 kW 3STM3-14

TAIFU TCP170 Centrifugal Pressure Pump 1.1 kW

TAIFU Submersible Pressure Pump 0.55 kW QDX1.5-24-0.55LA

TAIFU 3” Solar DC Bore Hole Pump 750W 72V DC

TAIFU Circulating Pump 120W

Understanding Flow, Pressure, and Total Dynamic Head (TDH)

Flow Rate – Volume moved per minute/hour (L/min or m³/h)
Pressure – Force to push water through pipes (1 bar ≈ 10m head)
TDH – Sum of lift height, pipe friction loss, and pressure required at outlets

Choosing by Application

Each pump type solves a different problem. Below is a technical breakdown of ideal uses and the correct TAIFU product to match:

Domestic Pressure Boosting

QB60 Peripheral Vane 0.37kW – Single tap or geyser boost
QB80 Peripheral Vane 0.75kW – Stronger pressure for multi-outlet homes
SGJ600 Stainless Pump 0.6kW – Ideal for moderate-size homes
SGJ800 Stainless Pump 0.8kW – Higher head applications, compact & efficient

Garden Irrigation & Tank Transfer

TCP170 Centrifugal 1.1kW
TCP200 Centrifugal 1.5kW – Robust for long horizontal runs

Borehole Applications (Clean Water)

2STM1-30 Borehole Pump 0.25kW – Shallow domestic boreholes
3STM3/14 Borehole Pump 0.37kW – Compact, high-head for narrow casings
4STM4/10 Borehole Pump 0.75kW – Medium-depth domestic/agri supply
4STM4/14 Borehole Pump 1.1kW – Long irrigation runs or deep bores

Solar Borehole Systems

3TSS1.5-65 250W / 24V
3TSS2-110 500W / 48V
3TSS2-150 750W / 72V – Suitable for off-grid farms with high lift

Dirty Water & Sump Drainage

WFD6-12 0.55kW – Handles solids and sludge
SP750W – Auto cut-off with float for stormwater pits

Circulating Hot Water

GRS15-11-Z Circulator 245W – Geyser loop or closed hot water systems

Fitting Matters: Installation Best Practices

Always size pipe diameter to reduce friction
Use non-return valves to maintain prime and protect controllers
For auto operation, pair with float switches or Vega Controllers

"Never size a pump on power alone — match the flow at the required head using the pump curve."

Need help calculating TDH or selecting a model? Visit your nearest Adendorff branch for assistance or use our online friction loss tools.

Part 2: Pump Sizing 101 – Flow, Head, and Friction Loss

Why Sizing Matters

Incorrectly sized pumps can lead to pressure drop, low flow at outlets, or motor burnout. Proper sizing ensures long service life and optimal water delivery at all taps, sprinklers, or appliances.

Step 1: Determine Your Required Flow Rate

Flow is the volume of water needed per minute. Estimate this based on the number and type of outlets:

Shower: 10–12 L/min
Tap: 10–15 L/min
Sprinkler: 15–25 L/min
4 sprinklers at once = 60–100 L/min

Step 2: Calculate Total Dynamic Head (TDH)

TDH = Vertical Lift + Friction Loss + Required Outlet Pressure

Vertical Lift: Height between water source and highest outlet
Friction Loss: Resistance from pipe length, diameter, bends
Outlet Pressure: E.g. 2.5 bar (25m) for sprinklers or strong showers

Example:

Borehole 40m deep + 200m horizontal pipe + sprinkler pressure (25m) = 40 + 18 (friction) + 25 = 83m TDH

Step 3: Use Pump Curves to Match Flow & Head

Pump performance curves show pressure at varying flow rates. Don’t size off max head or max flow — find where your required flow intersects your required head.

Look for a curve that hits your operating point (e.g. 40 L/min @ 83m).

Quick Reference: Domestic Sizing Guide

Home Type	Flow (L/min)	Pressure (bar)	Estimated Head (m)
1 Bed, 1 Bath	20–30	2.0–2.5	25–30
3 Bed, 1 Bath	40–50	2.5	30–35
3 Bed, 2 Bath + Garden	50–70	3.0	35–45
Large Home w/ Irrigation	80–120	3.5–4.0	50–60

Final Tip

"Oversizing slightly is safer than falling short — but never oversize too much, or risk short cycling and inefficiency."

In Part 3, we’ll look at physical setup and installation best practices to get every pump performing at its peak.

Part 3: Installation Guidelines – Surface vs Submersible Best Practices

Surface Pump Setup

Mount Close to Source: Keep suction lift short and direct
Use Non-Return Valve (NRV): Always install on the suction side
Prime Before Starting: Fill the pump and suction line with water
Secure Mounting: Place on solid, vibration-free base
Use Flex Hoses: Helps prevent stress on pipe joints

Submersible Pump Setup

Fully Submerged: Never run dry — check min depth requirement
Rope Support: Use a nylon rope, not the power cable, for suspension
Vertical Mount: Align the pump upright in borehole or tank
Float Switch: Ensure free movement for automatic start/stop
Use a Control Box (if needed): Especially for deep or high-load setups

Float Switch & Controller Tips

Vertical Mounting: Most controllers must be upright
Secure Cables: Avoid float tangling or snagging
Match Logic: NO/NC wiring must match system control setup
Use After-Pump NRVs: Especially with pressure switches

Electrical Safety Checklist

Ensure correct voltage & frequency match
Use certified electrician for hard-wiring jobs
Install earth leakage protection
Use waterproof joints for submersibles

"A poorly installed pump — even if it's the right size — can still fail. Installation matters as much as selection."

Part 4: Solar Pumping Systems – Off-Grid Water the Smart Way

What is a Solar Pump System?

Solar pumps use photovoltaic (PV) panels to convert sunlight into electricity, powering a DC pump for water delivery — ideal for remote boreholes, livestock tanks, or day-use irrigation.

System Components

Solar Panels: Provide the voltage and power to drive the pump
Controller or MPPT Inverter: Manages voltage, current, and protections
Pump: Submersible DC pump (e.g., TAIFU 3TSS Series)
Storage Tank (optional): Used to collect water for night or high-demand use

Matching Panels to Pump

Match Voltage: 24V, 48V, 72V based on pump spec
Wattage: Must exceed pump demand for reliable startup
Minimum Sunlight: System assumes 4–6 hours of usable sun per day

Example Configurations

3TSS1.5-65 (250W, 24V) + 2×150W panels → Small off-grid water transfer
3TSS2-110 (500W, 48V) + 4×150W panels → Medium borehole supply
3TSS2-150 (750W, 72V) + 6×150W panels → Deep lift or long-distance delivery

Common Solar Pitfalls

Running AC pumps off solar without inverter
Underpowering the panel array
Ignoring proper panel angle or orientation
No tank storage for cloudy days or night use

"Solar pump systems are silent, sustainable, and ideal for rural South Africa — but only if sized and set up correctly."

Part 5: Troubleshooting TAIFU Pumps – Fast Fixes for Common Issues

General Checklist Before Troubleshooting

Check power supply (voltage, circuit breaker, wiring)
Confirm pump is primed (for surface types)
Inspect pipes and joints for blockages or leaks
Verify system head vs. pump rating

Peripheral Pumps

Weak pressure: Airlock or impeller dirty → Re-prime & clean
No water output: No NRV or suction issue → Install NRV, check lift
Noisy: Cavitation → Check for leaks or incorrect installation

Centrifugal Pumps

Low flow: Small pipe or impeller block → Upsize pipe, clean pump
Won’t self-prime: Not self-priming → Manually fill and add foot valve
Loses prime overnight: Leaky foot valve → Replace valve

Multistage Pumps

No pressure: Air in system → Bleed air and check for blockages
Sudden pressure loss: Controller fault → Inspect or replace
Tripping power: Undersized wiring or overload → Check electrical spec

Submersible Pumps

No water: Float stuck or not submerged → Adjust float, check water level
Tripping DB: Cable damage or overload → Test insulation, check current
Weak flow: Clogged screen or undersized → Clean intake, verify sizing

Dirty Water Submersibles

Keeps clogging: Wrong pump type → Use vortex impeller model
No auto cut-off: Float issue → Secure or replace float
Overheating: Running in shallow water → Ensure full submersion

Circulating Pumps

No hot water: Airlock or timer off → Bleed system, check control
Continuous run: Wrong wiring → Verify thermostat or timer logic

"The majority of pump failures are installation or setup related — not manufacturing defects. Start your diagnostics with the basics."