FlowForge
水中汚水ポンプの設計と設置
水中式を掘り下げます：密閉モーターが水中でどう冷却されるか、シールとケーブル引込みに求められる条件、ガイドレールと据付ベンドの仕組み、フロート制御・交互運転・設置深さの決め方。水中式と陸上式の比較は汚水ポンプの総合ガイドから。本ページは供給案内で小売店ではありません。
The submersible form: pump and motor in the sump
Why choose a submersible
The pump and motor are one sealed unit that sits on the sump floor. There is no suction pipe to prime, no pump room to build and little noise. This page is about that form only. For the choice between submersible and non-submersible, and for impeller types, read the general sewage pump guide.
Cooling in the sump
The motor is cooled by the liquid around it, sometimes with a cooling jacket that sends pumped liquid around the motor casing. That is why a submersible must stay covered while it runs. A pump that is not covered can overheat.
Shaft seals, cable entry and motor protection
Shaft seals
A double mechanical seal with an oil chamber between the faces is common, so the liquid does not reach the motor. Seal faces are chosen for abrasive and chemical duty, and a seal-leak sensor can warn before water enters the motor.
Cable and cable entry
The power cable enters through a sealed gland. The cable jacket must suit the liquid and be long enough to reach the control panel without a joint under water. Give the sump depth and the route to the panel.
Thermal protection
Motor windings often carry a thermal switch that stops the motor on overheating. It protects against blocked impellers and low liquid level but is not a substitute for level control.
Materials
Cast iron housings are common; stainless steel is used for more corrosive liquid. Confirm the housing, impeller, seal and cable materials against the actual wastewater.
Guide rail, base elbow, depth and installation
Guide rail and base elbow
In a guide-rail system the pump slides down rails and seats on a fixed base elbow connected to the discharge pipe. The pump can be lifted out for service without entering the sump.
Free-standing and portable
Smaller sumps often use a pump that stands on its own base or hangs on a chain, with a flexible or rigid discharge. It is simpler but harder to lift out of a deep pit.
Installation depth
Sump depth sets the cable length, the lifting chain or rail length and the start and stop levels. The pump needs enough cover to stay flooded and enough room below the inlet to avoid sucking debris.
Discharge and check valve
A check valve on the discharge stops the column of liquid from running back. A gate valve lets you isolate the pump for service. Both sit outside the sump.
Float and level control, duplex sets, and running dry
Float and level control
Floats or a level sensor start the pump at a high level and stop it at a low level. The gap between them sets starts per hour, so too narrow a gap means short cycling and wear. A separate high-level float can drive an alarm.
Duplex sets
Two pumps alternate, so wear is shared, and the second pump runs if the first fails or the level keeps rising. Duplex is common where a failure would cause overflow.
Running dry
Running dry removes the cooling and can overheat the motor and the seals within a short time. Set the stop level above the pump, fit a low-level cut-off, and do not rely on thermal protection alone.
Solids and blockage
A blocked impeller overloads the motor. Choose the solids passage and impeller type for the fluid, as described on the general guide, and plan for lifting the pump to clear a block.
Submersible sewage pump checklist
Send these fields on the inquiry form. The pump spec guide has the general RFQ brief.
Sump size and depth
Plan size, depth, inlet height and cable route to the panel.
Fluid and solids
Sewage, effluent or drainage, largest solid and any fibers.
Flow and head
Required flow and total head including static lift and pipe losses.
Installation style
Guide rail, free-standing or portable, single or duplex.
Control and supply
Float or sensor, alarm; voltage, phase, frequency and cable length.
Branding and packaging
Private label, carton or crate lots and quantity.
Catalog SKUs closest to submersible duty
Existing catalog pumps with studio reference images. Neither is described as a dedicated sewage pump; cable, float, flow and head are quoted to your duty sheet.
What the catalog covers
The catalog lists a submersible drainage pump described for pits and light sewage and a self-priming pump for dirty water. Neither is described as a dedicated submersible sewage pump, so that duty is quoted to the duty sheet. The general guide is on the sewage pump page.
Two ways to buy
OEM and private label
Building a submersible pump range under your own brand? Start from a duty sheet. See Custom OEM for options and the private-label hub for housing, label and packaging.
Wholesale supply
Buying in crate lots for distribution or installation? The wholesale hub covers lots and spares. MOQ is quoted by SKU, not as a site-wide number.
Submersible sewage pump FAQ
Do you sell submersible sewage pumps to consumers?
No. This is OEM and wholesale supply for brands, distributors and contractors, with no cart and no public price. Send a duty sheet on the inquiry form.
How is a submersible pump motor cooled?
By the liquid around it, sometimes through a cooling jacket. The pump must stay covered while it runs.
What happens if a submersible pump runs dry?
The motor loses its cooling and the seals lose their lubrication, so both can overheat within a short time. Use a low-level cut-off and set the stop level above the pump.
What is a guide rail system?
The pump slides down rails and seats on a fixed base elbow on the discharge pipe, so it can be lifted out for service without entering the sump.
When do I need a duplex set?
When a failure would cause overflow or the inflow can exceed one pump. Two pumps alternate to share wear, and the second takes over if needed.
Can you private-label a submersible pump or supply it wholesale?
Yes. OEM and private-label work is quoted from a duty sheet, and lots are quoted by SKU. See private label and wholesale.
ポンプ工場見積が必要ですか？
流体、デューティシートまたはSKU、数量、国を送付。営業日通常24時間以内。