Tank Tee Setup: Proper Pressure Tank Plumbing Configuration

What Is a Tank Tee?

A tank tee is a specialized plumbing fitting that connects your pressure tank to the rest of the water system. While it looks simple, the tank tee serves several critical functions:

• Connects the pressure tank to supply and distribution piping
• Provides mounting points for the pressure switch and gauge
• Ensures accurate pressure sensing by positioning controls at the tank
• May include relief valve, drain valve, and check valve ports

Why "At the Tank" Matters

The pressure switch must sense actual tank pressure—not pressure affected by flow through pipes. When water flows, friction creates pressure drop. If your switch senses pressure in a flowing line instead of at the tank, it may:

• Turn the pump on too soon (pressure reads lower than actual)
• Turn the pump off too late (overshooting cutoff pressure)
• Cause erratic cycling
• Damage the pump over time

Tank Tee Components

Standard Tank Tee Features

A typical tank tee includes:

Types of Tank Tees

Basic Tank Tee

Simple cross or tee fitting with 1/4" ports for switch and gauge. Most common for residential systems.

Tank Tee with Integral Check Valve

Includes a built-in check valve to prevent backflow from the tank to the well. Useful when a check valve isn't installed at the wellhead.

Union Tank Tee

Includes union connections for easy tank removal without cutting pipes. Recommended for serviceability.

Tank Tee with Sampling Port

Includes a dedicated port for water testing samples. Required in some jurisdictions for periodic testing.

Proper Installation Layout

Recommended Flow Path

Water should flow through the system in this sequence:

1. Well/Pump → supply line from the well
2. Check valve → prevents backflow to well (if not at wellhead)
3. Tank tee inlet → water enters the tee
4. Pressure tank → connected to tee, stores water under pressure
5. Tank tee outlet → water exits to house
6. Shutoff valve → isolation for service
7. Distribution → to house and treatment equipment

Pressure Switch Placement

The pressure switch connects to a port on the tank tee that's:

• Not in the direct flow path
• Connected to the tank side of the tee
• Oriented to allow moisture to drain (prevents switch damage)

The switch should be positioned so the diaphragm points downward or horizontal—never with the sensing port facing up where water can collect.

Pressure Gauge Placement

Install the gauge where you can easily see it. Many tank tees have a dedicated gauge port. The gauge should:

• Be visible without bending or crouching
• Have a shutoff cock for easy replacement
• Match the system's pressure range (0-100 psi typical)

Common Installation Mistakes

1. Pressure Switch Not at Tank

Installing the pressure switch on a pipe away from the tank causes inaccurate pressure readings during flow. The switch may short cycle the pump.

Fix: Always mount the switch on the tank tee or directly on the tank fitting.

2. Check Valve in Wrong Location

Installing the check valve downstream of the tank tee (between tee and house) traps pressure in the tank when the pump stops. This causes:

• Tank can't fill properly
• Pump runs against closed system
• Possible pump damage

Fix: Check valve goes upstream of the tank tee (between well and tee), or use a tank tee with integral check valve.

3. Undersized Piping

Using smaller pipes than the tank tee's rated size creates restrictions that:

• Reduce flow capacity
• Cause pressure drops during high demand
• Make the system work harder

Fix: Match pipe size to tank tee size throughout the system.

4. No Unions for Service

Hard-piping everything makes tank replacement a nightmare. You'll have to cut pipes to remove the tank.

Fix: Install a union between the tank tee and tank, and consider a union tank tee design. See our union fittings guide.

5. Pressure Switch Tube Too Long

Using a long tube or nipple between the tank tee and pressure switch creates a "dead leg" where water can stagnate and corrode the switch.

Fix: Keep the connection as short as possible—directly to the tee is best.

6. Inadequate Support

The tank tee and connected piping carry significant weight and stress. Without proper support:

• Joints can fail
• Pipes can move and vibrate
• Tank connection can crack

Fix: Support pipes within 12" of the tank tee. Use hangers or straps rated for the pipe material and water weight.

Sizing Your Tank Tee

Tank tee size should match your system's pipe size and flow requirements:

Don't undersize—a restricted tank tee creates a bottleneck that affects the whole system.

Tank Tee Materials

Brass

• Pros: Durable, corrosion-resistant, traditional
• Cons: Higher cost, may contain lead in older fittings
• Best for: Most residential applications

Stainless Steel

• Pros: Very durable, completely corrosion-resistant
• Cons: Highest cost
• Best for: Corrosive water, commercial applications

Plastic (Polypropylene/PVC)

• Pros: Lowest cost, no corrosion
• Cons: Can crack under stress, some pressure limitations
• Best for: Budget installations, non-potable systems

For potable water systems, ensure any brass fittings are lead-free (NSF/ANSI 61 certified).

Installation Steps

Basic Tank Tee Installation

1. Turn off power to the pump and relieve system pressure
2. Position the tank near its final location
3. Apply thread sealant (Teflon tape or pipe dope) to all male threads
4. Install the tank tee onto the tank fitting (hand-tight plus 1-2 turns)
5. Connect supply pipe from well (with check valve upstream)
6. Connect distribution pipe to house
7. Install pressure switch on designated port
8. Install pressure gauge
9. Support all pipes adequately
10. Turn on power and check for leaks
11. Verify pressure settings match tank pre-charge

We install Well-X-Trol (Amtrol) and Flexcon pressure tanks — industry-leading bladder tanks that outlast standard diaphragm models. Proper sizing with a quality tank can double your pump's lifespan.

Frequently Asked Questions