A spiral nozzle forms a full-cone or hollow-cone spray by directing liquid over an exposed helical surface. The open passage is useful when a process needs broad coverage, high flow or better solids passage than a nozzle with an internal vane. Selection still depends on the liquid, duty-point flow and pressure, spray geometry, material, connection and maintenance plan.
This guide explains the mechanism and engineering decisions. For available Jeltecn sizes and quotation data, go directly to the spiral spray nozzle product page.
What Is a Spiral Nozzle?
A spiral nozzle is an industrial spray nozzle with an exposed helical or stepped impact surface. Liquid leaves the inlet and is divided across successive spiral turns, producing overlapping spray sheets. Depending on the geometry, those sheets form a filled cone or an annular cone.
The term describes the geometry, not a guarantee about performance. Spiral nozzles are sometimes marketed as pigtail, desulfurization, anti-clogging or high-flow nozzles, but the process engineer should select by verified model data rather than by a trade name.
How Does a Spiral Nozzle Work?
Liquid pressure provides the energy that moves the fluid through the inlet and across the spiral surface. Each turn redirects part of the stream into a circular sheet. The sheets expand and overlap downstream to create the specified cone pattern.
There is no internal vane in the main flow path. This provides comparatively open passage and fewer internal parts, which can reduce blockage sensitivity when properly sized. It does not eliminate blockage from oversized particles, fibers, crystallization, scale or shutdown deposits.
What changes the real installed spray?
- Pressure measured at the nozzle rather than at the pump.
- Liquid density, viscosity, surface tension, temperature and solids.
- Orifice and spiral geometry of the selected model.
- Spray distance, orientation, nearby walls and nozzle overlap.
- Gas flow or crosswind acting on the droplets.
- Erosion, deposits or physical damage to the discharge surface.
Full-Cone vs Hollow-Cone Spiral Nozzles
| Criterion | Full-cone spiral | Hollow-cone spiral |
|---|---|---|
| Pattern | Liquid is distributed throughout the cone volume. | Liquid is concentrated toward the outer ring. |
| Starting use case | Volumetric washing, gas scrubbing, cooling zones and dust wetting. | Annular contact, perimeter coverage or selected cooling duties. |
| Main design check | Distribution, overlap, flow density and dry zones. | Ring coverage, spray distance, carryover and wall contact. |
| Selection limit | Pattern name and angle do not replace a model-specific flow and coverage review. | |
For a broader comparison with vane-type cone designs, read spiral nozzle vs conventional full-cone nozzle.
How to Select a Spiral Spray Nozzle
Start with the process duty, then size the nozzle around the installed hydraulic and geometric conditions. Selecting only by thread size or nominal angle can produce the wrong flow, coverage or droplet behavior.
| Selection variable | Engineering question | Why it matters |
|---|---|---|
| Liquid | What are the chemistry, concentration, temperature, viscosity, specific gravity and solids? | These inputs affect material, flow behavior, wear, deposits and compatibility. |
| Flow | What flow is required per nozzle and for the complete header? | Total flow determines pump, piping and nozzle quantity requirements. |
| Pressure | What are the minimum, normal and maximum pressures at the nozzle inlet? | Pressure changes flow and can alter the developed spray. |
| Pattern | Is filled-volume or annular distribution required? | This distinguishes full-cone from hollow-cone duty. |
| Angle and distance | What area must be covered at the installed spray distance? | Angle, distance and overlap determine wall wetting and dry zones. |
| Connection | Is the installation NPT or BSPT, male or female? | Thread forms are not interchangeable and affect sealing and fit. |
| Maintenance | Can the nozzle be isolated, flushed, removed and inspected? | Access is part of reliable design for slurry or depositing liquids. |
Use the dedicated spiral nozzle sizing, material and thread selection guide when preparing an order specification.
Published Jeltecn product range
| Parameter | Current published option |
|---|---|
| Pattern | Full cone or hollow cone |
| Spray angle | 60°–180° |
| Thread size | 1/4–4 inch |
| Connection | Male or female; BSPT or NPT |
| Orifice diameter | 2.4–63.5 mm |
| Water pressure | 0.7–25 bar |
| Published capacity | 2.6–11,960 L/h; confirm the model and duty point |
| Materials | 303 stainless steel, 316 stainless steel, brass and PVDF |
These values define the family range, not a promise that every combination is available in one model. Check the applicable data sheet or request a model review.
Where Are Spiral Nozzles Used?
Gas scrubbing and flue-gas treatment
Spiral nozzles are evaluated where scrubbing liquid must cover a duct or vessel while handling recirculated liquid. The system designer must confirm liquid-to-gas duty, gas velocity, residence path, wall clearance, mist elimination and material compatibility.
Flue-gas desulfurization
FGD duty adds slurry passage, abrasion, deposits and corrosion to the selection problem. See the FGD spiral nozzle selection guide for application-specific inputs.
Dust suppression
For crushers, conveyors and transfer points, the spray must be matched to dust behavior, wind, target location, water availability and runoff limits. See spiral nozzles for dust suppression.
Cooling, quenching, washing and rinsing
These duties require the process engineer to balance coverage, droplet behavior, heat or mass transfer, wetting, carryover and available residence distance. Water testing is useful for confirming pattern and flow, but it may not reproduce the behavior of the actual process liquid or hot gas.
How Should Material Be Selected?
Choose material from the actual chemistry, temperature, abrasion and mechanical environment. Stainless steel, brass and PVDF have different corrosion, temperature and strength boundaries; a generic material label is not a compatibility approval.
Provide the chemical name, concentration, operating and upset temperature, suspended solids and any site restrictions. The process owner should approve compatibility, supported by applicable supplier data or controlled testing where failure risk is material.
Common Spiral Nozzle Problems and First Checks
| Observed condition | Check first |
|---|---|
| Reduced or uneven flow | Inlet pressure, upstream strainer, orifice, deposits and piping obstruction. |
| Dry zones or wall wetting | Nozzle angle, spray distance, orientation, overlap, gas flow and mounting position. |
| Pattern distortion | Physical damage, partial deposits, low pressure or interference near the outlet. |
| Flow increases over time | Erosion or wear at the orifice and spiral surface. |
| Repeated deposit buildup | Liquid chemistry, shutdown flushing, temperature zones and inspection interval. |
Isolate and depressurize the system under the site’s approved procedure before removal or inspection. Do not insert hard tools that can change the orifice or damage the spiral surface.
For low flow, distorted pattern, dry zones or repeated deposits, use the spiral nozzle troubleshooting and maintenance guide before changing the nozzle model.
Spiral Nozzle RFQ Checklist
- Application and required process result.
- Liquid name, concentration, temperature, viscosity, specific gravity and solids.
- Required flow per nozzle and pressure at the nozzle.
- Full-cone or hollow-cone pattern and preferred spray angle.
- Spray distance, coverage dimensions, nozzle quantity and arrangement.
- NPT or BSPT connection, thread size and male or female requirement.
- Material restrictions, operating cycle and maintenance access.
- Quantity, delivery destination and installation drawing or photo.
Frequently Asked Questions
Are spiral nozzles clog-proof?
No. Their open geometry can improve solids passage, but reliability still depends on the particle size, deposits, selected orifice, filtration and maintenance.
Can I select a nozzle only from the spray angle?
No. Flow, pressure, pattern, distance, liquid properties and installed geometry must be considered together.
Are NPT and BSPT threads interchangeable?
No. Confirm the mating thread standard before ordering and use the site’s approved sealing method.
Who supplies Jeltecn products?
Jeltecn is a registered brand of Melinco Precision Technology Co., Ltd. Quotations should identify the required product and commercial entity information.
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