Oil-Free Air Compressor for PET Bottle Blowing

Oil-Free Air Compressor for PET Bottle Blowing

Oil-free air compressor for PET bottle blowing — 4.0 MPa blowing air, 2.7–150 m³/min; oil-free control air 0.60–1.20 MPa. 58 models, 37–2000 kW, 380V/6kV/10kV. Three-stage, four-stage, LG.ZW combo.

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Oil-Free Air Compressor for PET Bottle Blowing — Two-Series Reciprocating System

Dedicated Oil-Free Compressed Air for Plastic Blow Moulding Lines · Blowing Air 4.0 MPa, 2.7–150 m³/min · Mould Control Air 0.60–1.20 MPa, 3–130 m³/min · 37–2000 kW

The oil-free air compressor for PET bottle blowing is a purpose-built two-series compressed air system engineered for the specific high-pressure and purity requirements of PET stretch-blow moulding machines, PP blow moulding lines, and plastic container forming equipment. The system covers two independent compressed air demands on every blow moulding production floor: a high-pressure oil-free blowing air supply at 4.0 MPa (40 bar) for stretching and blowing PET preforms into finished bottle shapes; and a separate medium-pressure oil-free control air supply at 0.60 to 1.20 MPa for mould clamping mechanisms, preform heating controls, and machine instrument air.

Series A — Plastic Blow Moulding Air Compressor: 43 standard models covering 2.7 m³/min to 150 m³/min at discharge pressure of 4.0 MPa (3.0 MPa optional), in three mechanical configurations: twin-column three-stage reciprocating (ZW, LW, DW, MW series); four-column four-stage reciprocating (4MW, MW four-column series); and twin-screw plus single-stage piston combination (LG.ZW integrated series). Drive power ranges from 37 kW to 1,700 kW with voltage options of 380 V, 6 kV, and 10 kV. Custom single-unit capacity up to 2,000 kW available on request.

Series B — Oil-Free Air Compressor for Mould and Instrument Air: 15 standard models covering 3 m³/min to 130 m³/min at discharge pressures of 0.60 to 1.20 MPa, using twin-column single-stage and two-stage configurations with PTFE piston rings and distance piece isolation for guaranteed zero oil carry-over. Drive power from 22 kW to 800 kW. Custom capacity up to 2,000 kW on request.

Oil-free air compressor for PET bottle blowing — three-stage reciprocating piston compressor supplying 4.0 MPa high-pressure blowing air for PET stretch-blow moulding machines and plastic container production lines
Oil-free reciprocating air compressor for PET bottle blowing — Series A blowing air at 4.0 MPa and Series B oil-free control air at 0.60–1.20 MPa for plastic blow moulding production lines
Oil-Free — PTFE Piston Rings
Blowing Air: 4.0 MPa
2.7–150 m³/min
Control Air: 0.60–1.20 MPa
58 Standard Models
37–2000 kW
380 V / 6 kV / 10 kV

Typical applications: PET stretch-blow moulding lines for water, beverage, juice, and edible oil bottles · PP and HDPE extrusion blow moulding for food containers · Linear and rotary PET blow moulding machines · Cosmetic and personal care bottle production · Pharmaceutical PET and PP container lines · Large-format PET bottle blowing for 5-gallon water jugs · Hot-fill PET bottle production

Series A — Oil-Free Air Compressor for Plastic Blow Moulding

High-Pressure Blowing Air · Discharge Pressure 4.0 MPa (3.0 MPa Optional) · Flow 2.7–150 m³/min

Series A models supply the high-pressure blowing air demand of PET stretch-blow moulding and plastic bottle production lines. Three mechanical configurations are available: twin-column three-stage (ZW, LW, DW, MW series — compact modular configuration for single-machine and small-line installations); four-column four-stage (4MW, MW four-column series — balanced high-flow configuration for large multi-machine blow moulding plants); and LG.ZW integrated series (twin-screw compressor for low-pressure first-stage plus single-stage piston for high-pressure second-stage — compact combined unit for medium-flow installations). Custom single-unit capacity up to 2,000 kW available on request.

No. Model Pattern Flow (m³/min) Pressure (MPa) Dimensions L×W×H (mm) Weight (t) Power (kW) Voltage (V)
1 ZW-2.7/40(30) Modular Twin-col. 3-stage 2.7 4.0 (3.0) 1530×1680×1375 2.80 37 380
2 ZW-4/40(30) Modular Twin-col. 3-stage 4 4.0 (3.0) 1920×1900×2580 4.50 45 380
3 LW-4/40(30) Modular Twin-col. 3-stage 4 4.0 (3.0) 3435×950×2006 2.70 45 380
4 LW-6/40(30) Modular Twin-col. 3-stage 6 4.0 (3.0) 3435×950×2006 2.70 65 380
5 LW-8/40(30) Modular Twin-col. 3-stage 8 4.0 (3.0) 3400×1550×2350 3.50 90 380
6 LW-10/40(30) Modular Twin-col. 3-stage 10 4.0 (3.0) 3400×1550×2350 3.50 110 380
7 LW-12/40(30) Modular Twin-col. 3-stage 12 4.0 (3.0) 3932×1695×2720 5.20 132 380
8 LW-16/40(30) Modular Twin-col. 3-stage 16 4.0 (3.0) Belt: 3932×1695×2720 / Coupling: 2800×3600×2450 5.50 185 380
9 LW-18/40(30) Modular Twin-col. 3-stage 18 4.0 (3.0) Belt: 3500×2600×1850 / Coupling: 2800×3600×2450 6.00 200 380/6K/10K
10 LW-20/40(30) Modular Twin-col. 3-stage 20 4.0 (3.0) Belt: 4545×1700×2450 / Coupling: 2800×3600×2450 8.00 220 380/6K/10K
11 LW-22/40(30) Modular Twin-col. 3-stage 22 4.0 (3.0) Belt: 4545×1700×2450 / Coupling: 3850×3100×2800 8.00 250 380/6K/10K
12 LW-23.5/40(30) Modular Twin-col. 3-stage 23.5 4.0 (3.0) Belt: 4545×1700×2450 / Coupling: 3850×3100×2800 8.00 250 380/6K/10K
13 LW-24/40(30) Modular Twin-col. 3-stage 24 4.0 (3.0) Belt: 4850×2250×2800 / Coupling: 3850×3100×2800 9.50 280 380/6K/10K
14 LW-25/40(30) Modular Twin-col. 3-stage 25 4.0 (3.0) Belt: 4850×2250×2800 / Coupling: 3850×3100×2800 9.50 280 380/6K/10K
15 LW-28/40(30) Twin-col. 3-stage 28 4.0 (3.0) 2960×1685×2335 6.50 315 380/6K/10K
16 DW-30/40(30) Twin-col. 4-stage 30 4.0 (3.0) 6145×3225×2335 11.00 355 6K/10K
17 DW-35/40(30) Twin-col. 4-stage 35 4.0 (3.0) 6585×3590×2095 13.00 400 6K/10K
18 DW-40/40(30) Twin-col. 4-stage 40 4.0 (3.0) 6585×3600×2100 13.00 450 6K/10K
19 DW-50/40(30) Twin-col. 4-stage 50 4.0 (3.0) 6585×3600×2100 13.00 550 6K/10K
20 DW-60/40(30) Twin-col. 4-stage 60 4.0 (3.0) 8500×4400×3020 17.00 650 6K/10K
21 DW-70/40(30) Twin-col. 4-stage 70 4.0 (3.0) 8500×2440×3020 18.00 750 6K/10K
22 MW-20/40(30) Modular Four-col. 4-stage 20 4.0 (3.0) 5000×3100×2600 16.50 200 380
23 MW-22/40(30) Modular Four-col. 4-stage 22 4.0 (3.0) 5000×3100×2600 17.00 220 380
24 MW-25/40(30) Modular Four-col. 4-stage 25 4.0 (3.0) 5000×3100×2600 17.50 250 380/6K/10K
25 MW-28/40(30) Modular Four-col. 4-stage 28 4.0 (3.0) 5000×3100×2600 18.00 280 380/6K/10K
26 MW-30/40(30) Modular Four-col. 4-stage 30 4.0 (3.0) 6000×3200×2600 21.00 315 380/6K/10K
27 MW-35/40(30) Modular Four-col. 4-stage 35 4.0 (3.0) 6000×3200×2600 25.00 355 380/6K/10K
28 MW-40/40(30) Modular Four-col. 4-stage 40 4.0 (3.0) 6500×3200×2600 26.00 400 6K/10K
29 MW-45/40(30) Modular Four-col. 4-stage 45 4.0 (3.0) 7000×3200×2600 28.00 450 6K/10K
30 MW-50/40(30) Modular Four-col. 4-stage 50 4.0 (3.0) 7500×3200×2600 30.00 500 6K/10K
31 4MW-90/40(30) Four-col. 4-stage 90 4.0 (3.0) 6800×3900×3200 26.00 1000 6K/10K
32 MW-100/40(30) Four-col. 4-stage 100 4.0 (3.0) 6800×3900×3200 26.00 1100 6K/10K
33 MW-120/40(30) Four-col. 4-stage 120 4.0 (3.0) 6800×3900×3200 26.00 1200 6K/10K
34 MW-150/40(30) Four-col. 4-stage 150 4.0 (3.0) 8500×3900×3200 27.00 1700 6K/10K
35 LG.ZW-6/40(30) Screw+piston combo 6 4.0 (3.0) 4000×2400×1850 4.20 72 380
36 LG.ZW-8/40(30) Screw+piston combo 8 4.0 (3.0) 4000×2400×1850 4.50 96 380
37 LG.ZW-10/40(30) Screw+piston combo 10 4.0 (3.0) 4000×2400×1850 6.50 132 380
38 LG.ZW-15/40(30) Screw+piston combo 15 4.0 (3.0) 4500×2400×1850 8.00 200 380
39 LG.ZW-20/40(30) Screw+piston combo 20 4.0 (3.0) 4500×2400×1850 10.00 280 380
40 LG.ZW-25/40(30) Screw+piston combo 25 4.0 (3.0) 4500×2400×1850 10.00 315 380
41 LG.ZW-30/40(30) Screw+piston combo 30 4.0 (3.0) 5500×2400×1850 12.00 370 380
42 LG.ZW-40/40(30) Screw+piston combo 40 4.0 (3.0) 6200×2400×1850 16.00 450 380
43 LG.ZW-50/40(30) Screw+piston combo 50 4.0 (3.0) 6200×2400×1850 17.00 565 380

Note: “(30)” in the model name indicates 3.0 MPa optional pressure rating available on the same frame. “Modular” designation indicates skid-mounted modular configuration for compact installation. LG.ZW series uses twin-screw low-pressure stage plus single-stage piston high-pressure stage in one integrated unit. Custom single-unit capacity within 11 kW to 2,000 kW available on request.

Series B — Oil-Free Air Compressor for Mould Clamping and Instrument Air

For Mould Mechanism Control and Instrument Air · Discharge Pressure 0.60–1.20 MPa · Flow 3–130 m³/min

Series B models supply the medium-pressure oil-free air for blow moulding machine clamping cylinders, preform oven control valves, conveyor positioning systems, and general plant instrument air. All 15 models use PTFE piston rings and distance piece isolation for guaranteed zero oil contamination. Custom capacity up to 2,000 kW on request.

No. Model Pattern Flow (m³/min) Pressure (MPa) Dimensions L×W×H (mm) Weight (t) Power (kW) Voltage (V)
1 ZW-3/8 Twin-col. single-stage 3 0.80 763×720×1274 0.58 22 380
2 ZW-6/10 Twin-col. two-stage 6 1.00 2340×910×2070 1.80 55 380
3 LW-10/10 Twin-col. two-stage 10 1.00 2340×910×2070 1.80 75 380
4 LW-15/10 Twin-col. two-stage 15 1.00 2630×1550×2332 3.00 132 380
5 LW-20/10 Twin-col. two-stage 20 1.00 2632×1550×2332 3.00 132 380
6 LW-25/12 Twin-col. two-stage 25 1.20 2760×1600×2190 3.70 190 380
7 LW-35/12 Twin-col. two-stage 35 1.20 3015×1655×2245 6.50 250 10K
8 LW-40/10 Twin-col. two-stage 40 1.00 2890×1600×2173 4.12 260 380
9 LW-50/8 Twin-col. two-stage 50 0.80 2630×16525×2235 6.50 315 380
10 LW-60/8 Twin-col. two-stage 60 0.80 2380×1500×2560 6.00 350 10K
11 DW-60/8 Twin-col. two-stage 60 0.80 5000×1800×1450 6.00 350 10K
12 DW-85/8 Twin-col. two-stage 85 0.80 5456×3518×2535 13.00 500 6K/10K
13 DW-100/8 Twin-col. two-stage 100 0.80 5456×3518×2535 13.00 600 6K/10K
14 DW-110/8 Twin-col. two-stage 110 0.80 5500×3518×2535 13.00 630 6K/10K
15 DW-130/8 Twin-col. two-stage 130 0.80 6000×3640×3000 18.00 800 6K/10K

Note: Custom single-unit capacity within 11 kW to 2,000 kW available on request for Series B. Both oil-free (PTFE piston rings) and standard lubricated configurations are available on Series B frames for non-oil-sensitive applications.

Why PET Bottle Blowing Demands High-Pressure Oil-Free Air

The PET Stretch-Blow Moulding Process

PET bottle production by stretch-blow moulding compresses a reheated PET preform between two stages: low-pressure pre-blowing at 0.6 to 1.0 MPa to initiate the bubble, then high-pressure final blowing at 3.0 to 4.0 MPa (30 to 40 bar) to stretch the softened preform radially and axially against the cold mould cavity walls, forming the precise bottle shape. The final blowing stage requires substantial air volume delivered at very high pressure in a short cycle time — typically 0.3 to 0.8 seconds per blow cycle. At a production rate of 20,000 to 80,000 bottles per hour on a modern high-speed rotary blow moulding machine, the total compressed air demand at 4.0 MPa is significant, easily reaching 20 to 60 m³/min of free air delivery for a fully loaded production line.

Oil contamination of the high-pressure blowing air is unacceptable in food, beverage, and pharmaceutical PET packaging applications. Oil mist carried into the bottle interior during blowing cannot be removed by subsequent rinsing — it becomes trapped in the finished container and contaminates the product filled into it. Regulatory food contact material standards and beverage industry codes of practice prohibit oil-contaminated blowing air, making oil-free compressed air the mandatory specification for all food and beverage PET bottle production.

Three Mechanical Configurations in Series A

At 4.0 MPa, reaching the required pressure ratio from atmospheric requires multiple compression stages. The twin-column three-stage configuration (ZW, LW series) uses three progressively smaller cylinders in series — LP, intermediate-pressure, and HP — with inter-stage cooling between each stage, achieving 4.0 MPa in a relatively compact twin-column frame suited to single-machine or small multi-machine installations. The four-column four-stage configuration (MW, DW, 4MW series) adds a fourth compression stage, which improves thermodynamic efficiency at very high pressure ratios and provides better inter-stage temperature management for large-flow applications requiring sustained high-output at 4.0 MPa. The LG.ZW combined series uses a twin-screw compressor as the low-pressure first stage (atmospheric to approximately 0.7 MPa) feeding a single-stage reciprocating piston as the high-pressure second stage (0.7 to 4.0 MPa) — this combination delivers better part-load efficiency than a pure reciprocating design because the screw stage can be VFD-controlled for variable-speed operation, while the piston stage handles the high-pressure duty efficiently.

5 Core Advantages of This PET Bottle Blowing Compressor System

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Intrinsically Oil-Free at 4.0 MPa

PTFE composite piston rings in all compression stages eliminate oil from the entire 4.0 MPa blowing air circuit. Unlike oil-injected high-pressure compressors that rely on multi-stage coalescing filters to achieve oil-free status, these oil-free reciprocating units contain no oil in the compression space at any stage — the blowing air delivered to the bottle mould cavity is free of hydrocarbons by design, providing the highest achievable food safety guarantee for PET beverage packaging.

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Three Mechanical Configurations — One Series

The three Series A configurations — twin-column three-stage, four-column four-stage, and LG.ZW combined screw-plus-piston — cover the full spectrum from small single-machine installations (ZW-2.7 at 37 kW) through large multi-line beverage plant stations (MW-150 at 1,700 kW). Choosing the right configuration for each scale of production avoids over-engineering a small line with heavy industrial machinery or under-powering a high-output beverage plant with undersized equipment.

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LG.ZW Combined Unit — Compact and Efficient

The LG.ZW series integrates a twin-screw low-pressure stage with a reciprocating high-pressure stage on a single skid, reducing installation footprint by approximately 30% compared with separate LP screw plus HP piston compressor combinations. The screw stage handles the bulk of the compression work efficiently at low-to-medium pressure ratios, while the piston stage handles the demanding final high-pressure compression to 4.0 MPa — combining the efficiency advantages of each technology for the pressure range where each performs best.

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Field-Maintainable in Production Environment

PTFE piston rings, valve plates, and inter-stage gaskets are all field-replaceable items that can be changed by plant maintenance staff during planned production stoppages. On a beverage bottling line where compressor downtime means lost production at thousands of bottles per hour, the ability to perform maintenance within a plant maintenance team without specialist contractors significantly reduces the risk of extended production loss from compressor-related stoppages.

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Medium-Voltage Options for Large Beverage Plants

Large PET beverage plants with multiple filling and blowing lines operating simultaneously require substantial electrical power. Models from 200 kW upward are available with 6 kV and 10 kV motor options for direct connection to medium-voltage plant substations, eliminating the need for low-voltage step-down transformer capacity for the compressor room and reducing total installed electrical cost for large-scale operations.

Typical Application Scenarios

Oil-free air compressor for PET bottle blowing application scenarios — beverage water bottle production, juice PET packaging lines, pharmaceutical PET container forming, cosmetic bottle blowing, edible oil bottle manufacturing
Oil-free reciprocating air compressor for PET bottle blowing — application scenarios including beverage bottling plants, pharmaceutical packaging, food container production, and cosmetic bottle manufacturing

Water and Beverage PET Bottle Production

Mineral water, purified water, carbonated beverages, juice, tea, and energy drinks represent the largest single application for PET bottle blowing compressed air. A typical 24,000 bottles-per-hour rotary blow moulding machine for 0.5-litre PET water bottles consumes approximately 8 to 12 m³/min of blowing air at 4.0 MPa. A large beverage plant running four blowing machines simultaneously would require Series A station capacity of 30 to 50 m³/min. The LW and DW modular series in the 10 to 50 m³/min range serve the majority of beverage PET bottle blowing requirements.

Series A: LW-10 to DW-50 | Series B: LW-10/10 to LW-20/10

Pharmaceutical and Healthcare PET Packaging

Pharmaceutical oral solid dose bottles, syrup bottles, IV solution containers, and medical diagnostic reagent bottles all require PET or PP blow moulding with certified oil-free blowing air as a GMP (Good Manufacturing Practice) requirement. The oil-free blowing air standard in pharmaceutical packaging is typically more stringent than beverage applications, requiring formal air quality testing and documentation as part of the facility qualification process. The smaller ZW and LW series models (2.7 to 15 m³/min) at 380 V serve pharmaceutical packaging lines where batch sizes and machine speeds are lower than high-volume beverage production.

Series A: ZW-2.7 to LW-12 | Series B: ZW-3/8 to LW-10/10

Edible Oil and Condiment PET Bottles

Edible oil, soy sauce, vinegar, cooking wine, and other food condiment PET containers are typically larger-format bottles (1 to 5 litres) with thick walls that require slightly higher blowing air volume per bottle than thin-wall water bottles. The 3.0 MPa optional pressure variant available on most Series A models is often sufficient for thick-wall cooking oil bottles where the lower blowing pressure is adequate to fully expand the heavy-wall PET preform, reducing energy consumption versus full 4.0 MPa operation. The LW-18 to LW-28 range suits medium-scale edible oil packaging lines.

Series A: LW-18 to DW-40 | Series B: LW-15/10 to LW-25/12

Large-Scale Beverage Plant Multi-Line Stations

Large-scale beverage manufacturing facilities running 8 to 20 PET blow moulding machines simultaneously require centralized high-pressure compressor stations with total capacity of 80 to 200 m³/min at 4.0 MPa. The four-column four-stage MW series (MW-20 to MW-150) and the heavy-duty 4MW-90 model are designed for these large centralized station applications. Multiple units operate in parallel with lead-lag control to match station output to actual machine demand as lines start, stop, and change over between bottle formats. The 6 kV and 10 kV motor options on large MW models are essential for direct medium-voltage connection in large beverage plant electrical systems.

Series A: MW-50 to MW-150, 4MW-90 | Series B: DW-85/8 to DW-130/8

How to Size a PET Bottle Blowing Compressed Air Station

1

Determine Blowing Pressure Requirement

PET bottle blowing pressure varies by preform wall thickness, bottle format, and machine type. Standard CSD (carbonated soft drink) and water bottles require 3.5 to 4.0 MPa. Large-format thick-wall bottles and handles may be satisfied at 3.0 MPa. The blow moulding machine manufacturer specifies the required blowing air pressure at the machine manifold; add 0.2 to 0.3 MPa for distribution and filter pressure reduction to arrive at the compressor discharge pressure. Most installations standardize on 4.0 MPa to cover all bottle formats on the same station.

2

Calculate Total Blowing Air Demand

Sum the free air delivery (FAD) requirement of each blow moulding machine on the line. The machine manufacturer provides FAD consumption at 4.0 MPa in m³/min or m³/h in their technical specification. For machines not yet specified, a rule of thumb is approximately 0.4 to 0.7 m³ of FAD per 1,000 bottles for standard 0.5-litre PET water bottles — adjust proportionally for larger bottle volumes. Add a 20% margin for peak demand, blowback, and future capacity growth.

3

Choose Series A Configuration

For total station FAD below 30 m³/min, LW three-stage modular units are the most compact and cost-effective option. For 30 to 70 m³/min, DW four-stage or MW four-column models provide better efficiency at sustained high output. For 70 to 150 m³/min, MW and 4MW four-column models are the primary choice. For medium-flow installations where installation footprint is constrained, the LG.ZW combined series (6 to 50 m³/min) offers the most compact solution while maintaining competitive energy efficiency through VFD-capable screw low-pressure staging.

4

Plan Air Treatment and Redundancy

Downstream of the high-pressure compressor, install: an after-cooler to reduce discharge air temperature to within 10 deg C of ambient; a high-pressure moisture separator and automatic drain to remove condensate; a high-pressure coalescing filter rated at 0.01 micron and oil content below 0.01 mg/m³ as a final verification stage; and a high-pressure air receiver of at least 5 to 8 times the compressor FAD in litres to buffer demand peaks. Plan for N plus 1 redundancy — at least one standby unit — because blowing air failure stops all blow moulding machines immediately, with significant production loss per hour of downtime.

Frequently Asked Questions — Oil-Free Air Compressor for PET Bottle Blowing

1. Why does PET bottle blowing require 4.0 MPa when most industrial air tools run at 0.7 MPa?

PET at blow moulding temperature (95 to 115 deg C) behaves as a tough, highly elastic semi-solid rather than a free-flowing liquid. To stretch it rapidly against a cold mould wall and hold it in the exact mould cavity shape while it solidifies, very high differential pressure is needed to overcome the material resistance of the biaxially oriented PET. At 3.5 to 4.0 MPa, the blowing air forces the softened PET to conform precisely to the mould cavity geometry within the 0.3 to 0.8 second blow cycle. Lower pressure would result in incomplete bottle formation, thick uneven walls, and rejected containers. Industrial pneumatic tools at 0.7 MPa work with much lower resistance mechanisms — compressed air flow rather than material deformation — so they require far less pressure.

2. What is the advantage of the LG.ZW combined screw-plus-piston series?

The LG.ZW combined series uses a twin-screw compressor to handle the first stage of compression from atmospheric to approximately 0.6 to 0.8 MPa, then passes the pre-compressed air to a single-stage piston compressor for the final compression to 4.0 MPa. This arrangement takes advantage of the screw compressor efficiency at low-to-medium pressure ratios (where screw machines perform best), combined with the piston compressor efficiency at high pressure ratios (where reciprocating pistons outperform screw machines). The result is lower total specific energy consumption compared with a pure multi-stage reciprocating design of the same capacity. Additionally, the screw stage can be fitted with a VFD (variable frequency drive) to modulate total station output in response to varying production line demand, reducing energy waste during partial-load operation.

3. Can blowback recovery be integrated with this compressor series?

Yes. Modern PET blow moulding machines use blowback recovery systems that capture the high-pressure air remaining in the bottle mould cavity at the end of each blow cycle — typically 2.0 to 3.0 MPa — and return it to a recovery receiver for reuse in the next pre-blow stage or to supplement the low-pressure instrument air supply. This recovered blowback air represents 20 to 35% of the total blowing air consumption, directly reducing compressor energy demand. When blowback recovery is installed on the blow moulding machines, the compressor station sizing should account for the reduced net FAD requirement from the high-pressure station. Our application engineering team can assist with sizing calculations that incorporate blowback recovery for specific machine types and production rates.

4. What PTFE ring service life is expected in the high-pressure stages?

At 4.0 MPa discharge pressure, the HP stage piston rings operate under more demanding thermal and mechanical conditions than low-pressure fermentation or instrument air compressors. With properly filtered, cooled inlet air and adequate cylinder cooling water maintained at 30 to 38 deg C, expected PTFE composite ring life in the HP stage of a three-stage or four-stage blowing air compressor is typically 1,500 to 3,000 hours before wear check and 3,000 to 5,000 hours before planned replacement. LP and intermediate-stage rings achieve longer service life due to lower operating pressure and temperature. Inlet air filtration quality is the most significant variable — dust or moisture contamination of inlet air accelerates PTFE ring wear in all stages. Detailed ring life estimates per model and stage are provided in the operation manual.

5. What warranty and spare parts support are available?

Standard 12-month warranty from commissioning covers manufacturing defects in materials and workmanship. A commissioning spare parts set — PTFE piston ring sets for all stages, valve plates and springs for all stages, inter-stage gasket sets, inlet filter elements — is strongly recommended with each unit order to ensure parts are available for the first scheduled ring and valve maintenance event. Given the high cost of blowing air station downtime in a beverage or pharmaceutical packaging plant, maintaining a site stock of HP stage PTFE ring sets and complete valve assemblies is standard practice for production-critical installations. Our logistics team can arrange spare parts stocking agreements for project sites with long supply chain lead times.

Ready to Specify an Oil-Free Blowing Air System for Your PET Bottle Line?

Our engineering team provides free blowing air station sizing for PET and plastic blow moulding projects — including total FAD calculation, blowback recovery allowance, configuration recommendation (three-stage, four-stage, or LG.ZW combined), air treatment specification, and electrical starting data. Factory-direct pricing, global export, and full project documentation.