Customer Ratings & Reviews | Lianyungang Zelvo Quartz Products Co., Ltd.

4.9/5.0

Based on 138+ Global Export Transactions Top Tier Supplier

Product Quality

4.9 / 5.0

Supplier Service

5.0 / 5.0

On-time Shipment

4.8 / 5.0

Dimensional Match

5.0 / 5.0

Export Packaging

4.9 / 5.0

On-Site Verified Factory Verified premises in Donghai, Jiangsu

≤ 2h Fast Technical Response Direct feedback from quartz engineers

37% Buyer Reorder Rate Serving North America, EU, Asia & Mideast

Real Buyer Testimonials

Verified Feedback From International Clients

Evaluations provided by research institutes, semiconductor fabs, laser manufacturers, and equipment OEMs across 30+ countries.

Materials Science Laboratory - Dr. Marcus H. United States • Verified Order

October 14, 2024

BET Quartz Bulb Sample Tube 6mm/9mm/12mm

“We ordered 100 units of custom BET quartz bulb sample tubes for our surface area characterization instruments. The dimensional match with our BELSORP-Max unit was seamless. Wall thickness is uniform throughout the spherical bulb, and thermal cycling up to 1050°C showed zero degradation or devitrification. Zero breakage on arrival thanks to their reinforced sponge-lined export box. Excellent craftsmanship!”

Specification: ±0.05mm tolerance Thermal Cycling: 1050°C Pass Packaging: Reinforced Wooden Box

Lianyungang Zelvo Quartz Products Co., Ltd. Response: Thank you for your continuous trust, Dr. Marcus. All BET tubes undergo optical micrometer verification before packing to ensure leak-tight fitting for adsorption ports. We look forward to our next collaboration!

Precision Optical Equipment GmbH - Klaus W. Germany • Verified Order

November 28, 2024

UV Fused Silica Optical Windows & Plates

“Top-level optical clarity. We tested the transmission spectrum from 200nm to 2500nm on our spectrophotometer, and the deep UV transmission exceeded 91% at 254nm. Surface flatness is within λ/4, and scratch-dig standards met 40/20 effortlessly. Zelvo Quartz is an exceptionally reliable production partner for laser optics.”

Grade: UV Fused Silica JGS1 Surface Quality: 40/20 Scratch-Dig Delivery: DDP to Frankfurt 7 Days

Lianyungang Zelvo Quartz Products Co., Ltd. Response: Herzlichen Dank, Klaus! We maintain strict grade separation between JGS1, JGS2, and JGS3 materials to ensure consistent UV-Vis transmission for optical components.

Semiconductor Wafer Processing Co. - Vincent T. Singapore • Verified Order

December 05, 2024

CVD Quartz Boat & Flanged Process Tube

“Drawing-based precision is spotless. We sent a technical STEP file with 25 slots for 4-inch wafers. The slot pitch, width, and parallelism were accurate down to ±0.08mm without any micro-burrs. Welding seams between the handle and carrier rods are solid and fully annealed. Fast communication and swift lead time.”

Purity: 99.995% High Purity SiO2 Laser Machining: Slotted Wafer Boat Inspection: Coordinate Measuring Machine (CMM)

Lianyungang Zelvo Quartz Products Co., Ltd. Response: Thank you Vincent! Laser slotting and ultrasonic cleanroom packing are standard for our semiconductor quartz fixtures. Ready for your 6-inch line whenever needed.

Thermal Engineering Solutions - David P. United Kingdom • Verified Order

January 09, 2025

Large Diameter Clear Quartz Furnace Tubes & Flanges

“Sourcing OD 150mm × 1800mm clear quartz furnace tubes with ground flange ends is normally difficult due to transit breakage. Zelvo packed each tube inside custom-molded high-density EPE foam and a plywood crate. They arrived in London without a single blemish. Perfect roundness and zero air lines or bubbles.”

Diameter: OD 150mm × Length 1800mm End Process: Ground Flat Flange Packaging: Shockproof Wooden Crate

Lianyungang Zelvo Quartz Products Co., Ltd. Response: Much appreciated David! We take extreme care in the packaging of long heavy-wall tubes to withstand intercontinental transit with full peace of mind.

Quality & Trust Assurance

Why International Buyers Rate Zelvo 4.9/5

Strict quality control from raw quartz sand to finished products, backed by documented testing procedures.

99.99% Certified Raw Material

Directly manufactured in Donghai, China's quartz capital, using top-tier natural quartz crystals and high-purity synthetic fused silica. Trace element impurity analysis is rigorously maintained below 20 ppm.

Full Flame Annealing & Stress Relief

Every welded, cut, bent, or drilled quartz component undergoes an automated annealing cycle up to 1215°C in electric furnaces to eliminate internal thermal stresses and prevent cracking under high heat.

Breakage-Free Export Standard

Custom molded foam shells, multi-layer bubble wrap, moisture desiccants, and fumigated solid timber crates ensure our quartz parts reach international laboratories intact and production-ready.

FAQ

Ratings & Ordering Questions

How does Zelvo Quartz ensure high product consistency?

Every batch of fused quartz is verified through optical spectrum analyzers, digital micrometers, and polariscopes to verify bubble-free purity, transmission rates, and strain-free annealing. Inspection photos and dimension reports are provided before dispatch.

What is your policy if quartz glass is damaged during international transit?

We maintain a less than 0.2% transit damage rate due to our specialized shockproof export crates. In the rare event of transit damage, send clear photos upon unpacking and our 100% replacement guarantee ensures free fast-track remake and expedited shipping.

Can I order custom prototypes with a 1-piece MOQ before bulk manufacturing?

Yes! We actively support R&D institutes, universities, and OEMs with a 1-piece minimum order quantity for drawing-based trials, laser drilling, and custom glass-blown quartz apparatus.

Onsite CheckVerified factory premises

4.9 / 5 RatingVerified buyer reviews

5 Export RegionsAmericas, Asia, Mid East, Europe

Ratings & Reviews