The ProTek DP7 hand diaphragm primer removes air from a centrifugal pump’s priming line so water can rise into the pump before operation. Its manually operated handle offers a straightforward priming method for water-transfer equipment without adding an electric primer motor.
Choose the DP7 for centrifugal pump systems using 4-, 5-, or 6-inch suction pipe. This pipe-size selection is separate from the primer’s own threaded connection. Check the pump layout, suction-line length, and available mounting space before ordering.
Manual priming with serviceable components
A lever and connecting rod move the rubber diaphragm, while two check valves direct airflow through the primer. The aluminum-alloy body keeps the unit portable, and the drain valve lets you empty retained fluid after use.
| Feature |
Benefit |
| Hand-operated diaphragm |
Prime the centrifugal pump without a powered primer drive. |
| Aluminum-alloy body |
Provides a lightweight primer for pump or skid mounting. |
| Drain valve |
Allows fluid to be cleared from the unit after use. |
Technical specifications
| Specification |
Value |
| Manufacturer part number |
DP7 |
| Product function |
Hand-operated centrifugal pump primer |
| Selected suction pipe sizes |
4, 5, and 6 inches |
| Body and diaphragm |
Aluminum-alloy body; rubber diaphragm |
| Unit dimensions, without handle |
10-7/8 × 9-5/16 × 12-1/4 inches |
| Primer connection |
3/4-inch NPT internal thread; 1-1/2-inch NPT external thread |
Plan the priming connections
The DP7 primes a separate centrifugal pump; it does not replace that pump. Provide an airtight priming line and enough access to operate the handle and reach the drain.
| Component |
Selection or use |
| Centrifugal pump or skid |
Mount the primer securely in an accessible position. |
| Priming hose or tubing |
Use non-collapsible hose or flexible tubing between the primer inlet and pump. |
| Cut-off valves |
Provide a valve in the priming line and a pump-discharge cut-off to prevent air entering during priming. |
Before ordering
| Check |
What to confirm |
| System fit |
Confirm suction-pipe size, primer thread connection, mounting space, and handle clearance. |
| Installation supplies |
Check the hose, fittings, valves, and mounting hardware needed for your installation. |
| Operation |
Close the primer drain before priming. Close the priming-line cut-off immediately after priming. |
| Maintenance |
Remove debris beneath the diaphragm and drain retained fluid after each use. Inspect for suction leaks if priming fails. |
Need help selecting a primer? Contact UnitedBuilt through online chat, email parts@unitedbuilt.com, or call 602-253-7750 with your pump model, suction-pipe size, and mounting arrangement.
