Connectors (Cross), Plastic

Quick Answer: A plastic cross connector is a four-way tubing fitting with four ribbed arms at right angles, used to join one flexible tube to three others at a single point. It serves air, water and vacuum lines built from rubber, PVC or silicone tubing.

Four-Way Junctions for Shared Supply Lines

The cross is the four-port member of this group of plastic tubing fittings. Where the T and Y connectors split one line into two, and the L-shaped connector simply turns a line through a right angle, the cross brings four openings together. Supply entering one arm leaves through the other three, so one tap, pump or vacuum source can feed several stations.

In teaching labs that usually means running an air pump to three aeration stones in parallel experiments, sending tap water through several condensers, or building a small vacuum manifold for more than one filtration set-up. Pressure is shared between the outlets, and the flow in each arm depends on the tubing attached to it, so a screw clip on each branch is the simple way to balance them.

Specifications

Applications

• Supplying air from one pump to several aquaria or aeration experiments
• Splitting cooling water between condensers in a row of distillation set-ups
• Building a vacuum manifold that serves more than one Buchner filtration flask
• Fluid-flow demonstrations in physics, showing how flow divides between branches of different resistance

Care & Handling

• Push each tube fully over the ribs of the cross connector and fit a hose clip wherever the line carries pump or tap pressure.
• Flush the fitting with clean water after salt solutions or growth media, so crystals and residue do not narrow the bore.
• Polypropylene fittings are generally autoclavable, but check this item’s rating before sterilising.
• Keep small fittings sorted by size in a labelled tray, which avoids forcing the wrong tubing onto a spigot.

Why Choose LabEquip

Technicians setting up shared air, water or vacuum services across several benches usually need a mix of cross, T and elbow fittings. LabEquip lists these shapes within the Lab Glassware range; give your tubing bore and quantities on the contact page.

Frequently Asked Questions

When should I use a cross instead of two T connectors?

A single cross makes a compact four-way junction with one fewer joint, so there is less tubing and fewer places to leak. Two T fittings joined by a short tube give the same branching but let you space the outlets apart, which helps when stations are further away.

Will each outlet get the same flow?

Not automatically. The flow divides according to the resistance of each branch, so a shorter or wider outlet tube takes more than its share. Fit a screw clip to each branch and adjust until the outlets match.

How do I match the connector to my tubing?

Compare the spigot with the internal bore of the tubing. The tube should need a little stretching to go on, which gives a firm grip; if it slides on loosely, choose a larger fitting or narrower tubing, because a loose joint leaks or pulls apart.

Can a plastic cross connector be used on a vacuum line?

Yes. A rigid plastic fitting holds its shape under laboratory vacuum; the tubing is usually the weak point. Use thick-walled vacuum tubing, which does not collapse, and place a trap bottle between the manifold and the pump.

Are plastic connectors suitable for Bunsen burner gas lines?

They should not be used on fuel gas. LPG and natural gas supplies need hoses and fittings intended for fuel gas under local safety rules. Plastic tubing connectors are meant for water, air and vacuum lines in experimental set-ups.

How do I remove tubing that has stuck to the connector?

Soak the joint in warm water to soften the tubing, then twist while pulling. If it still will not move, slit the tubing lengthwise with the blade angled away from the fitting and your hand, and peel it off. Levering hard can snap a plastic spigot.

Last Updated: September 2026