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Safety Cue
Task-specific safety guidance for ordinary work hazards.
Project 07
Replace Angle Stop Valves and Supply Lines
Shut off, remove, and replace one accessible fixture angle stop and its compatible flexible supply connector, verifying the pipe stub-out, the new valve installation, and the connector routing under static and operating pressure.
Field Cue System
These cues appear at the point of work. They identify safety, code, manufacturer, and measurement issues before they become water damage, injury, or failed inspections.
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Critical Safety Cue
Serious injury, scalding, electrical shock, or major property damage is possible.
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Field Safety Cue
Practical work-area safety: lighting, footing, ventilation, and housekeeping.
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Code Alert
Local requirements vary. Verify permit, inspection, and jurisdictional rules.
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Manufacturer Cue
Follow product-specific instructions for valves, tools, and equipment.
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Measurement Cue
Reference-point, clearance, and verification guidance.
Job Overview
This project qualifies you to replace one accessible fixture angle stop valve and its flexible supply connector under controlled, code-compliant conditions. The finished work product is one replaced valve and connector assembly on an inspected pipe stub-out, tested under both static and operating pressure and left leak-free at every disturbed connection.
You will identify the fixture, pipe material, and existing valve connection; shut off, drain, and protect the work area using the Chapter 1 sequence; remove the old valve using the method specific to its connection type; inspect the exposed pipe stub-out; install the replacement valve using the approved connection method for the project; select and route a listed flexible supply connector; restore water slowly; and inspect the completed assembly under static and operating conditions.
This project builds directly on the isolation and drain-down skills from Chapter 1 and the pipe-preparation and joining skills from Chapters 3 through 6. It prepares you for the fixture-installation projects in Chapters 9 through 13, each of which depends on a correctly installed, accessible fixture stop.
Skills You Will Demonstrate
- PL-037 — Shut off the fixture supply using the correct upstream valve and verify isolation before disconnecting any component.
- PL-038 — Remove the old stop valve using the method specific to its connection type without damaging the pipe stub-out.
- PL-039 — Install the new stop valve using the approved threaded, compression, soldered, push-fit, or PEX method specified for the project.
- PL-040 — Install a listed flexible supply line of the correct material, length, and end connections without kinking, twisting, or stressing the connector.
- PL-041 — Restore water to the fixture supply slowly and purge air through the fixture before full-flow operation.
- PL-042 — Inspect the completed valve and connector assembly for leaks under static and operating conditions.
Where This Skill Fits
Every fixture project later in this book — the bathroom faucet and pop-up drain in Chapter 10, the toilet set in Chapter 11, and the capstone bathroom in Chapter 20 — depends on an accessible, operable, leak-free fixture stop already in place. Replacing a stop valve is one of the most frequently performed residential plumbing repairs, and it is the point at which many careful installers still cause a leak: at the valve-to-pipe connection, or at the connector-to-fixture connection.
The isolation, drain-down, and documentation discipline from Chapter 1 applies directly here. The joining method used to install the new valve is the same method taught for that pipe material in Chapters 4 through 6; this project does not teach a new joining method, it applies the one already learned to a stop-valve installation.
Scope and Intended Use
This project covers:
- identifying the fixture, pipe material, existing valve connection, new valve type, connector size, and fixture-inlet requirement
- shutting off, draining, and protecting the work area using the Chapter 1 sequence
- removing one existing accessible angle stop valve using the method specific to its connection type
- inspecting the exposed pipe stub-out for support, length, corrosion, and condition
- installing one replacement angle stop valve using the threaded, compression, soldered, push-fit, or PEX method specified for the project
- selecting and installing one listed flexible supply connector between the new valve and the fixture
- restoring water slowly, purging air, and inspecting the completed assembly under static and operating conditions
This project does not authorize the learner to:
- cut into or extend concealed supply piping beyond the accessible stub-out — that work belongs to the applicable pipe-joining chapter and is outside this project's boundary
- proceed when the pipe stub-out is severely corroded, cracked, shortened beyond use, loose in the wall, or connected by an unrecognized method
- replace a valve serving a system that cannot be confidently isolated or identified
- substitute an unlisted connector, an incompatible valve connection type, or a valve not rated for the pipe material and service
Any pipe stub-out condition that fails inspection in this chapter must be corrected, repaired, or escalated to a qualified professional before the replacement valve is installed.
Reference Conventions
Establish these references before any valve is disconnected, and do not change the defined work boundary mid-project.
| Term | Definition |
|---|---|
| Pipe stub-out | The exposed section of supply piping projecting from the wall or floor to which the fixture stop valve is connected |
| Existing valve connection | The method by which the current valve attaches to the stub-out: threaded, compression, soldered, push-fit, or PEX |
| Replacement valve connection | The method specified for the project by which the new valve will attach to the stub-out; may match or differ from the existing connection |
| Fixture-inlet requirement | The connector size and end-fitting type required at the fixture supply inlet |
| Backup support | Holding a fitting, adapter, or pipe stationary with a second wrench while another connection is loosened or tightened, to prevent the pipe from twisting in the wall |
| Stop-work condition | Any observed pipe or valve failure that must halt the project until corrected or escalated, defined in this chapter's failure-point section |
Work Boundary and Valve Record
Before disconnecting any component, record the defined work boundary and the selected components directly on the Angle Stop Replacement Worksheet:
Fixture: ______ Pipe material: ______ Existing valve connection: ______ Replacement valve connection method: ______
New connector size / length: ______ Date started: ____________ Builder name: ____________
Prerequisites
- Completed Chapter 1 work-area isolation, drain-down, and protection sequence for the fixture being serviced
- A completed Work-Area Readiness Worksheet confirming isolation, drainage, and hazard control at this fixture location
- Familiarity with the pipe-joining method that will be used to install the replacement valve, as taught in Chapters 3 through 6
- A replacement valve and connector confirmed compatible with the existing pipe material, size, and fixture-inlet requirement
- Basic hand tools and PPE listed in the Tools, Equipment, Materials, and PPE tables above
- A stop-work decision authority — the learner, supervisor, or licensed professional who will be notified if a stop-work condition is found
Common Field Fundamentals
Replacing an angle stop valve always follows the same core sequence regardless of pipe material or valve connection type: isolate, remove, inspect the stub-out, install, connect, restore, and verify. The connection method used at Step 10 of the work order below is the one specific variable — it must match the pipe material and the project specification, not be substituted freely.
IsolationFixture supply shut off, drained, and verified before disconnection
RemovalOld valve removed using the method specific to its connection type
Stub-out checkExposed pipe inspected for support, length, and condition
Valve installNew valve installed using the approved connection method for the project
ConnectorListed flexible connector routed without kinks, twists, or strain
Restore waterWater restored slowly with the new stop closed, then purged through the fixture
Static testConnections inspected under standing pressure before operation
Operating testValve operated through its range with the fixture flowing, then reinspected
Backup Support and Connection Control
Every threaded or union connection in this project — the old valve coming off, the new valve going on, and both ends of the flexible connector — must be loosened and tightened using a backup wrench on the adjacent fitting or pipe. A pipe stub-out that twists in the wall during valve removal or installation can crack a concealed joint that will not be discovered until later.
PL-037 – PL-042
Fixture Stop Valve and Supply Connector Replacement
Replace Angle Stop Valves and Supply Lines
A. Finished-Project Specification
Quantity: one replacement angle stop valve installed on one inspected pipe stub-out using the project-specified connection method, connected to the fixture with one listed flexible supply connector, tested and documented under static and operating pressure.
B. Component Schedule
| Component | Quantity | Material | Finished Size | Preparation |
|---|---|---|---|---|
| Angle stop valve | 1 | Compatible with pipe material and service, as specified for the project | Sized to the stub-out and connector outlet specified | Inspected for correct connection type before installation |
| Flexible supply connector | 1 | Listed material rated for the fixture's temperature and pressure service | Length and end-fitting sizes matched to the valve outlet and fixture inlet | Inspected for damage before routing |
| Thread sealant or joining materials | As required | Specific to the selected valve connection method | N/A | Applied only to the designated sealing surfaces |
C. Material Takeoff
- Valve: one replacement angle stop valve matched to the pipe material, size, and connection method specified for the project.
- Connector: one listed flexible supply connector of the correct material, length, and end-fitting sizes for the fixture.
- Joining materials: thread sealant, solder and flux, push-fit fitting, or PEX ring/clamp, according to the connection method specified for the project; do not substitute a different method's materials.
- Documentation: one Angle Stop Replacement Worksheet per project, plus a photograph of the original and replacement installations.
D. Acceptance Standards
| Check | Standard |
|---|---|
| Stub-out condition | Structurally supported, correct length, free of corrosion or cracking before valve installation |
| Valve installation | Installed using the project-specified connection method, oriented toward the fixture without stressing the pipe |
| Connector routing | No kinks, twists, stretching, or contact with sharp edges; correct length for the installed position |
| Static pressure test | No leakage at the valve-to-pipe connection or either connector end under standing pressure |
| Operating test | No leakage during valve operation and fixture flow; valve opens and closes through its full accessible range |
| Documentation | Angle Stop Replacement Worksheet complete with component, connection method, and test entries |
E. Fixture and Connection Identification
- Identify the fixture, pipe material, existing valve connection, new valve type, connector size, and fixture-inlet requirement. Record each item on the worksheet before proceeding.
- Confirm that the replacement valve is approved for the pipe material and intended service. Verify the manufacturer listing before installation.
F. Isolation, Removal, and Stub-Out Inspection
- Shut off, drain, depressurize, and protect the area according to Chapter 1. Verify isolation by direct observation before continuing.
- Verify that the pipe stub-out is structurally supported and long enough for the selected valve. Do not proceed if the stub-out is unsupported or too short.
- Disconnect the flexible supply line from the fixture and valve while controlling residual water. Direct released water into a bucket or absorbent towel.
- Hold the existing valve or adapter with the correct backup tool. Prevent the stub-out from twisting during removal.
- Remove the old valve using the method specific to its connection type. Do not apply excessive force or an incompatible removal technique.
- Stop work if the pipe is severely corroded, cracked, shortened beyond use, loose in the wall, or connected by an unrecognized method. Escalate per the Failure Points section before continuing.
- Clean and inspect the exposed pipe without reducing wall thickness or damaging the sealing surface. Confirm a sound, clean stub-out before installing the new valve.
G. Replacement Valve Installation
- Install the replacement valve using the approved threaded, compression, soldered, push-fit, or PEX method specified for the project. Follow the exact joining procedure taught for that method in the applicable chapter.
- Orient the valve outlet toward the fixture without exceeding the permitted adjustment or stressing the pipe. Confirm the outlet position accommodates the connector without a forced bend.
- Close the valve before restoring building pressure. Confirm the valve is fully closed by feel and position.
H. Flexible Connector Installation
- Select a listed flexible connector of the correct material, length, end sizes, temperature rating, and service. Confirm the selection against the fixture-inlet requirement recorded in Step 1.
- Route the connector without twisting, kinking, stretching, abrasion, or contact with sharp edges. Confirm a smooth, unstressed path between the valve and the fixture inlet.
- Start connector threads by hand and tighten according to the connector and fixture instructions. Use a backup wrench at the valve outlet where required.
I. Restoring Water and Static Inspection
- Restore water slowly while the new stop remains closed. Observe the valve body and connector connections for leakage as pressure builds.
- Inspect the valve-to-pipe connection under static pressure. Confirm no leakage before opening the valve.
J. Operating Inspection and Correction
- Open the stop slowly and purge air through the fixture. Run the fixture until air is cleared and flow is steady.
- Inspect both connector ends and the valve stem under static and operating conditions. Check for leakage at each end fitting and at the valve stem while the fixture is flowing.
- Operate the valve through its intended range and verify accessible shutoff. Confirm the valve closes fully and reopens smoothly.
- Correct leakage only after re-isolating and depressurizing the system. Do not tighten a leaking connection under pressure.
- Dry the area and perform a delayed reinspection. Return after normal use to confirm no leakage has developed.
- Label or document the new valve and connector installation. Complete every field on the Angle Stop Replacement Worksheet.
Common Readiness Inspection
Inspect every completed valve and connector replacement using the same checks regardless of which fixture or pipe material the project involves.
- Stub-out check: confirm the exposed pipe was structurally sound, supported, and correctly sized before the new valve was installed.
- Valve check: confirm the replacement valve was installed using the project-specified connection method and closes and opens fully.
- Connector check: confirm the flexible connector is free of kinks, twists, and contact with sharp edges.
- Static test check: confirm no leakage was observed at any disturbed connection under standing pressure.
- Operating test check: confirm no leakage was observed at any disturbed connection during fixture flow and valve operation.
- Documentation check: confirm the Angle Stop Replacement Worksheet is fully completed and signed.
Complete the Angle Stop Replacement Worksheet in the Inspection Checklist section below before beginning Project 08.
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Failure Points and Troubleshooting
Cleanup
This project ends with the replacement valve and connector installed, tested, and left ready for normal fixture use.
- Dispose of the old valve, connector, and any cut pipe sections properly
- Clean and dry the cabinet or wall area disturbed during the work
- Confirm the new valve is left in the correct operating position for normal fixture use
- Wipe down tools and store unused sealant, solder, or fitting materials
- Store the Angle Stop Replacement Worksheet with the fixture's maintenance records
Field Terms
- Pipe Stub-Out
- The exposed section of supply piping projecting from the wall or floor to which the fixture stop valve is connected.
- Existing Valve Connection
- The method by which the current valve attaches to the stub-out: threaded, compression, soldered, push-fit, or PEX.
- Replacement Valve Connection
- The method specified for the project by which the new valve will attach to the stub-out.
- Fixture-Inlet Requirement
- The connector size and end-fitting type required at the fixture supply inlet.
- Backup Support
- Holding a fitting, adapter, or pipe stationary with a second wrench while another connection is loosened or tightened.
- Flexible Supply Connector
- A listed flexible line connecting the fixture stop valve to the fixture supply inlet.
- Static Pressure Test
- Inspection of a connection for leakage under standing, non-flowing water pressure.
- Angle Stop Replacement Worksheet
- The document recording the fixture, components, connection method, and test results for this project.
Skill Check
- Why must isolation be verified before disconnecting the old valve or connector, rather than assumed from the valve position?
- What conditions in the pipe stub-out require the learner to stop work rather than install the replacement valve?
- Why must a backup wrench be used at the stub-out when removing or installing a threaded valve connection?
- Why should a flexible supply connector be replaced whenever the stop valve is replaced, even if it appears undamaged?
- What must be confirmed about the valve outlet orientation before installing the flexible connector?
- Why is the valve closed before building pressure is restored, and opened only after the static test passes?
- What is the difference between the static pressure test and the operating test in this project?
- Why must a leaking connection be corrected only after re-isolating and depressurizing the system?
- What must the learner do if the replacement valve does not fully close after installation?
- What information must be recorded on the Angle Stop Replacement Worksheet before this project is considered complete?
Competency Rubric
| Competency | Independent Pass Standard | Not Demonstrated | With Assistance | Independently |
|---|---|---|---|---|
| PL-037 | Shuts off the fixture supply using the correct upstream valve and verifies isolation before disconnecting any component | |||
| PL-038 | Removes the old stop valve using the method specific to its connection type without damaging the pipe stub-out | |||
| PL-039 | Installs the new stop valve using the approved threaded, compression, soldered, push-fit, or PEX method specified for the project | |||
| PL-040 | Installs a listed flexible supply line of the correct material, length, and end connections without kinking, twisting, or stressing the connector | |||
| PL-041 | Restores water to the fixture supply slowly and purges air through the fixture before full-flow operation | |||
| PL-042 | Inspects the completed valve and connector assembly for leaks under static and operating conditions |
Mark one column per competency. Only Demonstrated Independently awards the competency; Demonstrated with Assistance authorizes additional supervised practice but does not complete the requirement.
Inspection Checklist — Angle Stop Replacement Worksheet
| Item | Target Condition | Result | Pass/Fail | Correction (if any) |
|---|---|---|---|---|
| Stub-out condition | Supported, correct length, free of corrosion or cracking | |||
| Valve installation | Installed using the project-specified connection method, correctly oriented | |||
| Connector routing | No kinks, twists, stretching, or abrasion | |||
| Static pressure test | No leakage at valve-to-pipe or connector connections | |||
| Operating test | No leakage during valve operation and fixture flow; full shutoff verified | |||
| Delayed reinspection | No leakage observed after normal use |
Unresolved issues and escalation plan: ____________________________________________
Installation declared complete: ______ (Pass/Fail) Date: ____________ Builder name: ____________
Performance Check
With the old valve removed, the stub-out inspected, the replacement valve and connector installed, and water restored, review the finished installation against the Acceptance Standards table and confirm the stub-out was structurally sound before installation, the valve was installed using the project-specified connection method and is correctly oriented, the connector is free of kinks, twists, and abrasion, no leakage is present at any disturbed connection under static pressure, no leakage is present during valve operation and fixture flow, and the delayed reinspection confirms a dry, leak-free condition. Complete the Angle Stop Replacement Worksheet and correct any failed item before beginning Project 08. If an item fails, identify whether the error occurred in stub-out preparation, valve installation, connector selection or routing, or pressure testing before correcting it and re-running the affected check.
Project Closeout
You have completed the seventh project in the residential plumbing sequence: replacing an angle stop valve and supply line. This project required you to shut off the fixture supply, remove the old stop valve, install a new stop valve, install a flexible supply line, restore water, and inspect for leaks (PL-037 through PL-042).
You now have a repeatable fixture-stop replacement procedure that applies to any pipe material and connection method taught earlier in this book. That procedure carries directly into the next project: assembling and testing a PVC drain-waste-vent branch using the approved fitting pattern, slope, and support requirements.
Confirm the new stop valve is left in the correct operating position, and retain your Angle Stop Replacement Worksheet as part of the fixture's maintenance record.