Delavan 70B 2.75GPH Solid Cone Nozzle 9/16-24 - 1338

High-Output 2.75 GPH Oil Nozzle for Reliable, Efficient Combustion

The Delavan 2.75 GPH nozzle is a high-flow oil burner nozzle designed to deliver exactly 2.75 gallons per hour of No. 2 heating oil at a standard 100 PSI pump pressure. It's available in multiple spray codes-from narrow 45° to wide 80° solid cone "B" configurations-giving technicians the flexibility to match virtually any large-format combustion chamber. This is a precision-engineered product built for one job: consistent, high-volume fuel delivery for larger residential and light commercial oil burners.

If you've been chasing combustion problems, fighting soot buildup, or dealing with undersized nozzles that can't keep up with your equipment's firing rate, the Delavan 2.75 GPH nozzle eliminates the guesswork. It has a flow rate of 2.75 gallons per hour at standard 100 PSI pressure, and it delivers that rated output reliably thanks to Delavan's tight manufacturing tolerances.

This product page focuses on genuine Delavan-branded nozzles offered through Barens, for installers and facility operators who need dependable 2.75 GPH performance they can trust right out of the sealed packaging.

Why You'll Love the Delavan 70B 2.75 GPH Nozzle

This is a workhorse nozzle size. If you're running higher-BTU boilers, large furnaces, or commercial heating equipment that demands serious fuel delivery, the 2.75 GPH sits right in the sweet spot between mid-range residential and full commercial firing rates.

• Stable high-BTU output – At 2.75 GPH measured at 100 PSI, this nozzle can support approximately 385,000 BTU/hour of input. That's enough to handle large heating loads, fast recovery times on hydronic storage tanks, and commercial air handlers without short cycling or struggling to maintain temperature. Delavan nozzles support a wide range of heating applications, and the 2.75 GPH size is particularly well-suited for systems that need sustained, heavy-duty output.

• Smoother ignition and flame shape – Solid cone nozzles deliver precise fuel atomization, and the Type B pattern creates a uniform fuel cloud inside the combustion head. Type B nozzles deliver droplets uniformly throughout the spray pattern, which means better light-off, fewer flameouts, and virtually no rumble at startup. The solid cone design reduces incomplete combustion, giving you a clean, stable flame from the moment the burner fires.

• Cleaner combustion and less soot – Precise atomization directly translates to lower smoke numbers. When fuel is broken into a fine, evenly distributed mist, you get efficient combustion that keeps heat exchangers, flue passages, and electrodes cleaner over the entire heating season. Less soot means less maintenance and better heat transfer efficiency across the board.

• Fewer nuisance service calls – A consistent spray pattern and accurate flow rate help maintain your draft and combustion settings throughout the season. That means fewer callbacks for technicians and more predictable consistent performance from the heating system.

• Drop-in compatibility – Delavan 2.75 GPH nozzles are machined to the standard 9/16-24 UNEF thread and common body dimensions, fitting oil burner guns used across North America without special adapters. Pull the old nozzle, thread in the new one, and you're ready for combustion testing.

What Makes the Delavan 70B 2.75 GPH Nozzle Different

Generic nozzles are a gamble. Inconsistent flow rates, uneven spray distribution, soft brass that wears out fast-cheap imports can drift 15–20% from their rated GPH, which means your combustion settings are wrong before you even fire the burner. Delavan nozzles are precision-engineered for reliable performance, and the difference shows up in every aspect of the build.

• Precision-orificed brass body – The nozzle features bi-metal construction with a brass body and stainless steel metering parts. The metering orifice and swirl chamber are tightly controlled so a 2.75 GPH Delavan actually delivers the rated flow at 100 PSI-not some approximation that forces you to compensate with air adjustments and pressure tweaks. Correct sizing and alignment are essential for efficiency, and Delavan builds that precision into every item that leaves the factory.

• Engineered solid-cone "B" spray pattern – For many high-fire burners, the solid cone 60°–80° at 2.75 GPH delivers a dense, evenly filled flame that's compatible with standard retention heads. Solid cone nozzles produce a uniform spray pattern that fills the combustion zone thoroughly. Worth noting: the spray pattern becomes hollow at flow rates above 8.00 GPH, but at 2.75 GPH you get a true, fully solid cone every time.

• Reliable performance at real-world pressures – Many systems are tuned between 100–150 PSI pump pressure. Flow increases with the square root of the pressure ratio, so at 140 PSI you can expect roughly 3.25–3.30 GPH from this nozzle. Delavan publishes flow charts so technicians can predict output at higher pressures for accurate firing-rate adjustments-no guesswork required.

• Backed by a specialist retailer – Barens keeps a broad stock of Delavan sizes and spray angles on hand, including multiple 2.75 GPH variants. That means you can match nozzles with filters, hoses, and test equipment for complete service kits, all from a single source that understands oil heat.

How the Delavan 70B 2.75 GPH Nozzle Works

The Delavan 2.75 GPH nozzle is a precision metering and atomizing device that sits at the business end of your oil burner assembly. It takes pump-pressurized fuel and converts it into a finely atomized spray cone that mixes with combustion air to produce a stable, efficient flame. Here's what happens inside:

1. Fuel enters the metering orifice – Pump-pressurized No. 2 heating oil, typically at 100 PSI, reaches the threaded nozzle and passes through a finely machined orifice calibrated to meter exactly 2.75 gallons per hour. Delavan nozzles deliver 0.50 to 0.85 gallons per minute depending on configuration, and the 2.75 GPH sits right in that operating window. The precision of this orifice is what separates a Delavan from a generic nozzle-it's the foundation of accurate fuel delivery.

2. Swirl chamber creates atomization – After passing through the orifice, fuel enters internal slots and swirl passages that spin the oil at high velocity. This rotational energy breaks the fuel stream into a conical mist of fine droplets. The size and uniformity of those droplets determine flame stability and how completely the fuel burns. They support efficient combustion in heating systems by ensuring fuel is thoroughly atomized before it ever reaches the flame zone.

3. Spray pattern fills the combustion head – The 2.75 GPH solid cone spray projects into the burner's retention head or turbulator, where it mixes with combustion air to form a stable, bright flame. Available spray patterns include Type A (Hollow Cone), Type B (Solid Cone), and Type W (Semi-Solid), so you can match the pattern to your specific burner head geometry. Type A nozzles concentrate droplets on the outer edge of the cone, while Type W nozzles provide an intermediate spray pattern between hollow and solid cones.

4. Consistent output over the heating cycle – As long as pump pressure and filtration are maintained, the nozzle keeps delivering roughly 2.75 gallons per hour, supporting predictable input BTUs and thermostat response. Maintaining a clean fuel supply line is essential for proper nozzle function-when the fuel stays clean, the nozzle delivers consistent performance hour after hour.

Product Details: Delavan 70B 2.75 GPH Oil Nozzle Specifications

Here are the key specs for easy reference-designed to be scannable on a phone or truck tablet so you can confirm compatibility before installation.

• Flow rate: 2.75 gallons per hour (GPH) at 100 PSI pump pressure. Actual flow rises if the burner is tuned above 100 PSI; technicians should reference Delavan flow charts when adjusting pressure for precise firing-rate calculations.

• Spray pattern options: Common solid-cone "B" choices at this firing rate include 45°B, 60°B, 70°B, and 80°B. Delavan nozzles feature a 70-degree spray pattern for efficient combustion as one of the most popular configurations. Angle selection depends on chamber size and burner head design-deeper chambers need narrower angles, wider heads need broader coverage.

• Operating pressure range: Typically suited for 100–150 PSI residential and light commercial burner pumps, with stable atomization over that range when clean fuel and filtration are maintained.

• Materials: Precision-machined brass body with stainless steel internal components (416 stainless orifice disc and distributor). This bi-metal construction provides durability and resists the erosion and corrosion that degrade cheaper nozzles over time.

• Fuel compatibility: No. 2 heating oil and low-sulfur heating oils. Delavan nozzles are typically used in oil-fired furnaces and boilers. They are also utilized in commercial pressure washers and waste oil heaters. Technicians should confirm suitability before using with blends like biodiesel or kerosene.

• Thread: Standard 9/16-24 UNEF with 5/8" hex body-fits common oil burner gun assemblies without adapters.

• Identification markings: "2.75", spray angle (e.g., "60"), and pattern code letter "B" appear on the nozzle hex and/or color-coded cap to avoid mix-ups during service. They help maintain system reliability across heating applications by preventing installation error.

• What's included: Single Delavan 2.75 GPH oil burner nozzle, factory-sealed in protective packaging, ready for installation. No extra adapters or tools are bundled with this item.

Who the Delavan 70B 2.75 GPH Nozzle Is For

This nozzle size is aimed squarely at higher-capacity oil-fired equipment where smaller nozzles simply can't keep up with the heat demand. If you're running anything in the 350,000–450,000 BTU/hour input range, this is your size.

• Oil heat service contractors and technicians – Field reliability and consistent calibration matter when you're running from job to job. Barens' stock of Delavan nozzles simplifies truck inventory planning-keep a few 2.75 GPH nozzles in multiple angles on hand and you're ready for any large-burner call without waiting on delivery.

• Facility and property managers – Apartment buildings, small commercial facilities, churches, and workshops with mid- to high-BTU boilers or furnaces often run 2.50–3.00 GPH firing rates. The 2.75 GPH Delavan gives these systems the fuel delivery they need for fast heat recovery and steady output through the coldest months.

• Industrial and agricultural operators – Waste oil heaters (where compatible and specified), high-output space heaters, grain dryers, and process heaters that require a robust 2.75 GPH firing rate all benefit from Delavan's proven atomization quality.

• DIY owners with existing large oil burners – While tuning and combustion testing should be left to licensed professionals, owners can read the 2.75 GPH spec on their existing nozzle to verify that a replacement matches the original rating. Proper tools and understanding are needed for self-installation, so consult a qualified technician if you're not experienced with oil burner service.

How to Choose the Right 2.75 GPH Delavan Nozzle for Your Burner

Getting the GPH right is only part of the equation. Angle and pattern matter just as much for safe, efficient combustion. The wrong combination can cause flame impingement, sooting, or dangerous operating conditions-even with the correct flow rate.

• Match the GPH to the appliance rating plate – Before shopping for a nozzle, check your burner's nameplate for the specified firing rate (BTU/hr and nozzle size). If it calls for 2.75 GPH, you're in the right place. Delavan nozzles must be installed according to the specific application's specifications-don't upsize or downsize without manufacturer guidance.

• Select the correct spray angle – Narrow angles (45°–60°) suit deeper, longer combustion chambers where you need the spray to reach further without hitting sidewalls. Wider angles (70°–80°) fill shallower combustion heads and work well with retention-style burners. Always follow the burner manufacturer's recommendations for angle selection.

• Choose the right spray pattern code – At 2.75 GPH, the solid-cone "B" is the most common choice for a stable, uniformly filled flame. Swapping to hollow "A" or semi-solid "W" patterns will change flame shape and combustion dynamics-only make that switch with proper combustion testing by a qualified technician. Professional service reduces the risk of misalignment and combustion error.

• Confirm fuel and system conditions – Before blaming the nozzle for combustion problems, check oil cleanliness, filter condition, pump output pressure, and draft. A contaminated fuel supply or worn pump can make even a brand-new Delavan nozzle underperform.

• Leverage Barens as a stocking source – Barens carries multiple 2.75 GPH variants across different angles and pattern codes, so technicians can fine-tune systems without long lead times. Having the right nozzle on hand when you need it means faster service and happier customers.

Installing and Setting Up a Delavan 70B 2.75 GPH Nozzle

Important: Oil burner work should be handled by qualified, licensed personnel. Installation should be carried out by a licensed technician. Improper setup can cause soot, smoke, carbon monoxide production, or unsafe operation. Proper installation of the nozzle is critical for achieving efficient oil combustion.

1. Prepare the burner assembly – Shut off power and fuel supply to the burner. Clean or replace fuel filters and verify pump pressure settings with a gauge. Installation ensures peak combustion efficiency and system safety only when the entire fuel train is in good working order before you touch the nozzle.

2. Remove the old nozzle correctly – Using the correct tools during installation prevents damage to the nozzle and burner components. Use a properly sized wrench on the nozzle hex while supporting the burner tube to prevent twisting. Inspect the removed nozzle for sooting, coking, or orifice distortion-these are clues about prior combustion quality.

3. Install the new Delavan 2.75 GPH nozzle – Hand-thread the nozzle first to avoid cross-threading, then snug to manufacturer torque recommendations. Keep the nozzle tip clean and free of fibers, lint, or debris. Cleaning a clogged nozzle with wires or compressed air is not recommended-always install a fresh nozzle rather than trying to salvage a contaminated one.

4. Reassemble and set electrode position – Check the burner manufacturer's specs for electrode gap and position relative to the nozzle tip and retention head. Misaligned electrodes cause ignition failure, delayed ignition, or poor flame establishment regardless of nozzle quality.

5. Test-fire and adjust combustion – A proper setup includes a smoke test, draft check, CO₂ or O₂ measurements, and fine-tuning of air damper and pump pressure so the 2.75 GPH nozzle runs cleanly. Document your readings-they become the baseline for future maintenance visits.

Keeping Your Delavan 70B 2.75 GPH Nozzle Performing Over Time

Even a high-quality Delavan nozzle is a wear item. High-pressure oil flow and heat exposure gradually erode the orifice and distributor slots, shifting spray pattern and flow rate in ways you can't see with the naked eye. Treat nozzle replacement as part of routine seasonal maintenance, not a repair.

• Schedule regular replacements – Annual replacement of the nozzle is recommended due to wear from high-pressure oil and heat. For high-duty applications that run extended hours, consider mid-season replacement as well. The cost of a new nozzle is trivial compared to a no-heat emergency call or a soot-damaged heat exchanger.

• Protect it with proper filtration – Clean oil filters, strainers, and water separators extend nozzle life dramatically. At 2.75 GPH, more fuel mass passes through the nozzle per hour, so any contamination has an amplified effect on spray quality and combustion efficiency.

• Monitor for combustion drift – Periodic smoke tests and efficiency measurements catch problems early. Subtle increases in smoke number, shifts in CO₂ readings, or changes in flame appearance usually indicate nozzle wear or partial blockage before they become serious issues.

• Store spares correctly – Keep spare Delavan 2.75 GPH nozzles in their original sealed containers, protected from dirt, moisture, and impact in service vehicles. A contaminated spare nozzle defeats the purpose of carrying one.

• Use Barens as a long-term supply partner – Maintaining standard stock of 2.75 GPH nozzles in multiple angles allows fast, on-the-spot replacements throughout the heating season. Barens keeps these nozzles in inventory so you're never waiting on a backorder when a customer's system is down.

Frequently Asked Questions About Delavan 70B 2.75 GPH Nozzles

Here are answers to the most common questions technicians and equipment owners ask about the Delavan 2.75 GPH nozzle.

Is 2.75 GPH too large for a typical home oil furnace? For most single-family residential furnaces, yes-typical home systems run 0.60–1.50 GPH nozzles. The 2.75 GPH size is designed for larger homes with high-BTU equipment, multi-family buildings, or small commercial heating systems. Always check the appliance rating plate before ordering. Installing an oversized nozzle in a small burner can overheat components, exceed combustion chamber capacity, and create dangerous operating conditions.

Can I swap a 2.50 GPH nozzle for a 2.75 GPH Delavan to get more heat? Increasing the firing rate affects combustion air balance, venting, draft, and safety margins. This kind of change should only be made under burner manufacturer guidance and with full combustion testing performed by a licensed technician. An upsized nozzle without corresponding air and draft adjustments will produce smoke, soot, and potentially dangerous carbon monoxide levels.

Does spray angle matter if the GPH is the same? Absolutely. Spray angle significantly affects flame shape and chamber coverage. A 2.75 GPH nozzle at 45° produces a tight, deep cone, while the same flow at 80° produces a wide, shallow pattern. Using the wrong angle can cause spray impingement on chamber walls, sooting, incomplete combustion, and even heat exchanger damage. The angle must match your specific burner head and combustion chamber geometry.

How often should I replace a 2.75 GPH Delavan nozzle? At least once per heating season for standard applications. In high-duty environments-equipment running extended hours daily-consider replacement every 1,000–1,500 burner hours or mid-season, whichever comes first. Cleaning a worn nozzle rarely restores original precision, especially at higher flow rates.

Where can I get genuine Delavan 2.75 GPH nozzles? Barens supplies authentic Delavan nozzles in a range of 2.75 GPH configurations-multiple angles, pattern codes, and materials-along with related oil-heat service components like filters, electrodes, and combustion test instruments. All rights to the Delavan brand and product specifications belong to the manufacturer.

Ready to Upgrade Your High-Output Burner?

Stop settling for inconsistent combustion, mystery-brand nozzles, or worn-out parts that are costing you fuel, service time, and customer trust. The Delavan 70B 2.75 GPH nozzle delivers the precise fuel atomization, uniform spray pattern, and reliable durability that large oil-fired systems demand-season after season.

If your current nozzle is more than a season old, has been viewed as "good enough," or came from a brand you can't verify, now is the time to return to a proven standard. A fresh Delavan 2.75 GPH nozzle restores burner performance, cuts soot formation, and gives you the combustion baseline you need for clean, efficient operation.

Add the Delavan 70B 2.75 GPH nozzle to your cart or service stock through Barens today. Whether you need a single replacement or a case of mixed angles for your truck inventory, Barens has the selection and the shopping experience to keep your heating operation running at peak efficiency all season long.