Ductile Iron Reducing Tee – Threaded Cast Fitting for Size Transition

By Nico Yin · Qingdao Zhaoyuqi Machinery Co., Ltd.

Overview

A reducing tee is a three-way pipe fitting in which the main run changes from one diameter to a smaller diameter, while a branch outlet allows flow to be diverted at 90°. Unlike a straight tee, this single casting performs two functions at once: it reduces the line size and creates a branch connection, eliminating the need for a separate reducer plus tee joint. Our reducing tees are produced by resin sand casting in ductile iron to ASTM A536 (typical grades 65-45-12 and 80-55-06) and to European grades EN-GJS-400-15, -450-10 and -500-7. Typical size combinations range from 2"×1" up to 12"×8", covering the most common demands of water supply, HVAC, fire protection, irrigation and industrial piping systems.

These fittings are widely used wherever a smaller branch line must be taken off a larger main — pump discharge headers, sprinkler zone feeds, compressor air lines and municipal distribution networks. Every threaded outlet is machined after casting to ASME B1.20.1 NPT or ISO 228 BSP, and the body can be supplied machined bare, hot-dip galvanized or with fusion-bonded epoxy coating for buried or corrosive service. Because we cast and machine in-house, non-standard reduction combinations and special branch angles are routinely handled as custom orders.

Specifications

Customization & Sampling

As a casting factory, we control pattern, molding, pouring and machining in one workflow. We can cut new patterns for non-listed reduction combinations, adjust wall thickness for higher pressure classes, or produce tees with special branch orientations. Pre-production samples with full dimensional reports are available before volume orders; sample lead time is typically 15–25 days depending on whether a new pattern is required.

Quality Inspection & Packaging

Each batch is verified against customer drawings: chemical composition from the melt, tensile and hardness coupons per ASTM A536, thread gauge checking on all machined outlets, and sand casting dimensional audit to ISO 8062. Surface coating thickness is measured for galvanized and epoxy finishes. Quality management conforms to ISO 9001:2015 requirements. Fittings are packed in woven bags or cartons, then palletized and stretch-wrapped; export seaworthy packing with steel-strapped plywood cases is available for heavier sizes.

FAQ

Q1: What does a "4"×2" reducing tee" mean?

It means the main run enters at 4" and continues (or reduces) at 2", with the 90° branch matched to one of the run ends. We can also customize the branch to a third size, e.g. 4"×2" run with a 1½" branch.

Q2: Can you make reduction combinations outside your standard list?

Yes. Because the fittings are sand cast from patterns we control, new run/branch combinations generally require only a modified or new pattern rather than new tooling, keeping cost and lead time reasonable.

Q3: How do I choose between a reducing tee and a reducer plus straight tee?

A one-piece reducing tee has fewer joints, fewer leak paths and lower installed labor cost. A reducer-plus-tee arrangement is only preferred when the two functions must be sourced separately or staged during construction.

Related Products

• Reducing Coupling

• 90° Reducing Elbow

• Street or Service Tee (Reducing)

• Concentric Reducer

• Coupling

Get a Quote

Send us your size combination, standard and coating requirements — our engineers will reply with a drawing-based quotation within 24 hours. WhatsApp: +86 185 6156 7088, or email us with your BOQ. Factory-direct pricing, MOQ-friendly trial orders.

Need a formal quotation? Send your Ductile Iron Reducing Tee drawing, quantity and target price through our request for quotation form — it goes straight to the foundry inbox, and we reply with a priced offer, material certificate draft and production lead time within one business day.