Graco 100474 Coupling Pipe — Overview & Compatibility
Compatible Machines
The Graco 100474 Coupling Pipe is a threaded fitting used across various Graco pump/manifold and proportioner assemblies. Confirm with your machine’s parts manual before ordering.
- Bulldog® 33:1 Airless Spray Pump (appears in parts breakdowns for select Bulldog pump assemblies)
- Graco 8900 Proportioner Series (listed in select proportioner manuals as “COUPLING, pipe”)
- Other Graco transfer/airless pump systems that require a 1-11½ NPT(M) pipe coupling in their fluid path
Product Description
The Graco 100474 Coupling Pipe is a male 1-11½ NPT pipe coupling used to connect fluid lines or components within Graco spray and proportioning equipment. It maintains a robust, leak-resistant connection when installed per equipment specifications.
Key Specifications
| Part Number | 100474 |
| Catalog Description | COUPLING, Pipe, 1-11½ NPT(M) |
| Thread Type | NPT (Male) |
| Typical Use | Fluid line / manifold connection on Graco airless and proportioner systems |
How to Confirm Fitment
- Match the thread callout in your manual to 1-11½ NPT(M).
- Verify the parts diagram explicitly lists 100474 at the connection you are servicing.
- Inspect mating ports for damage and ensure pressure rating and materials meet your application.
Why Choose Genuine Graco
- Correct geometry and tolerances for Graco assemblies
- Reliable sealing when installed with appropriate thread sealant (if specified)
- Supports long-term system integrity and maintenance standards
Frequently Asked Questions
The 100474 Coupling Pipe is specified as 1-11½ NPT(M) (male National Pipe Thread, 11.5 TPI). Always confirm thread type and size against your equipment manual before installation.
This part is commonly used in Bulldog® 33:1, 8900 Proportioner, and other Graco systems that call for a 1-11½ NPT(M) coupling. For certainty, check your parts diagram; if it lists 100474, this is the correct coupling.
Follow your machine manual. Many NPT connections require a compatible thread sealant (or tape) to achieve a leak-free seal. Avoid over-application and keep sealant out of the fluid path.
A generic part may physically fit if the thread type/size and pressure rating match, but genuine Graco parts help ensure proper geometry, reliability, and compliance with service standards.
Clean threads, use the recommended sealant if specified, hand-start to prevent cross-threading, then tighten to spec. After pressurizing the system, check for leaks and re-torque if needed.
