Water make-up vessels must match system volume, pressure band and temperature swing; an undersized bladder tank can drive frequent pump cycling and unstable loop pressure.
YONGFAN JFDY Constant-Pressure Water Make-Up Unit provides usable regulating volume (Vt from 0.06 to 3.10 m³) with replaceable food-grade butyl bladders across 0.6, 1.0, and 1.6 MPa working-pressure classes.
Total volume V is not all available. Gas cushion permanently occupies vessel volume, so regulating volume Vt is substantially smaller (e.g. JFDY-1000: V=1.40 m³, Vt=0.49 m³).
Selecting pressure class only from building height ignores tank location, pump pressure effects, minimum high-point head, and relief limits.
If pre-charge is too high, the bladder cannot accept water. If too low, water occupies the vessel early, collapsing usable pressure-hold range.
JFDY is specifically the bladder pressure vessel. Pumps, sensors, control panels, and valves must be selected separately unless ordered as a skid.
| Model | Tank Ø × H (mm) | Total Volume V (m³) | Regulating Volume Vt (m³) | Working Pressure Classes | Net Weight (0.6 / 1.0 / 1.6 MPa) |
|---|---|---|---|---|---|
| JFDY-400 | 400 × 1460 | 0.20 | 0.06 | 0.6 / 1.0 / 1.6 MPa | 175 / 190 / 230 kg |
| JFDY-600 | 600 × 1820 | 0.35 | 0.11 | 0.6 / 1.0 / 1.6 MPa | 206 / 223 / 265 kg |
| JFDY-800 | 800 × 2250 | 0.82 | 0.26 | 0.6 / 1.0 / 1.6 MPa | 330 / 350 / 520 kg |
| JFDY-1000 | 1000 × 2550 | 1.40 | 0.49 | 0.6 / 1.0 / 1.6 MPa | 500 / 613 / 850 kg |
| JFDY-1200 | 1200 × 2780 | 2.50 | 0.80 | 0.6 / 1.0 / 1.6 MPa | 700 / 943 / 1187 kg |
| JFDY-1400 | 1400 × 2950 | 3.46 | 1.20 | 0.6 / 1.0 / 1.6 MPa | 900 / 1200 / 1600 kg |
| JFDY-1600 | 1600 × 3360 | 5.00 | 2.00 | 0.6 / 1.0 / 1.6 MPa | 1220 / 1802 / 2210 kg |
| JFDY-2000 | 2000 × 3850 | 8.53 | 3.10 | 0.6 / 1.0 / 1.6 MPa | 1700 / 2600 / 3700 kg |
*Standard JFDY vessels are vertical with bottom connection. Horizontal custom versions and multi-tank split configurations available on request for low-headroom plant rooms.
Standard construction uses Q235-B or Q345R pressure-vessel carbon steel. Stainless steel SS304 is available on request. Internal surface is shot-blasted to Sa 2.5 and epoxy-coated.
Standard membrane is a replaceable food-grade butyl rubber bladder conforming to GB/T 17219. High-temperature EPDM bladders are available for heating duties above 80 °C.
Pre-charged with dry nitrogen to 70–80% of system lower setpoint. Gauge pressure should always be verified on site with the water side completely drained.
Total loop water volume (m³) across piping, coils, boilers, and chillers.
Minimum fill temperature and maximum operating water temperature (°C).
Lower cut-in pressure (P1) and upper cut-out pressure (P2) in MPa.
Ceiling headroom, doorway clearance, and vertical vs. horizontal orientation.
YONGFAN application engineers will calculate acceptance volume, check pre-charge, and provide dimensioned submittal drawings.
Longitudinal and circumferential seams welded with automated submerged-arc process and radiographic/ultrasonic testing.
Internal shell is shot-blasted to Sa 2.5 before multi-pass epoxy coating application to prevent shell corrosion.
Each completed vessel is tested at 1.5× design pressure and held for 30 minutes with zero allowable pressure drop.
Bladders inspected against GB/T 17219 for elongation, tensile strength, and hygienic safety for potable water contact.
No. JFDY is the bladder pressure vessel. A complete make-up set can add separately selected pumps, pressure switches/transmitters, a control panel, and valves.
Total volume V is the complete internal shell volume. Vt is the usable water exchange between lower and upper setpoints. For JFDY-1000, total V is 1.40 m³ while Vt is 0.49 m³.
JFDY-2000 is the largest published vertical size, with 8.53 m³ total volume, 3.10 m³ regulating volume, a 2000 mm diameter, and 3850 mm height.
Typically 70–80% of the system lower cut-in setpoint. Final pre-charge should follow project hydraulic schedules and be checked with the water side drained.
Yes. Horizontal versions are available on request with revised drawings, saddle supports, and connection points.
Use Pressure Stabilizing & Expansion Units (JFWP) when an integrated skid with pumps, expansion management, and PLC controls is required.
Do not select the vessel from total volume V while ignoring the usable regulating volume Vt.
Do not use standard butyl bladders above 80 °C without confirming EPDM bladder upgrades.
Never add gas while the vessel is water-loaded; gauge pressure will not reflect true pre-charge.
Do not treat JFDY as a complete make-up skid unless pumps and controls are explicitly ordered.
Send your system water volume, operating temperature range, and lower/upper pressure setpoints. YONGFAN application engineers will calculate usable regulating volume and provide certified drawings.
