Diaphragm Pressure Tank 200L Supplier in the Philippines for Commercial Booster Systems

A 200L diaphragm pressure tank sits on the discharge side of a booster set and holds a cushion of pre-charged air behind a flexible membrane. When the pumps stop, that trapped air pushes stored water back into the riser, so small draws are served without starting a motor.

The number that governs your design is not the 200 litre nameplate, it is usable drawdown. Set the precharge at 38 psi with the controller cutting in at 40 psi and cutting out at 60 psi, and a 200L tank returns roughly 51.6 litres of usable water per cycle, about 26 percent of nominal volume. The differential drives everything: widen the cut-out to 80 psi on the same precharge and drawdown rises to roughly 81 litres, while narrowing to a 40/50 psi band drops it under 30 litres on the identical vessel. Against a 0.5 litre per second trickle demand, 51.6 litres buys about 103 seconds of pump-off time, comfortably clearing the one minute minimum most motor and contactor manufacturers assume. Undersize the tank and the same duty produces dozens of starts per hour, which burns contactors, overheats windings on direct-on-line starters, and shortens mechanical seal life. This is why 200L is a common specification point for mid-rise residential, small hotel, and light commercial commercial booster pump systems in the Philippines, sitting above the 100L units used on single-family systems.

Pressure tanks in this class differ more than the shared 200 litre label suggests, so our quotations pin down each variable. Membrane type is the first: a fixed diaphragm is sealed into the shell and cannot be swapped, while a replaceable diaphragm or full bladder can be changed in the field without replacing the vessel, which matters on a plant room you expect to service for a decade. Second is maximum working pressure, which must exceed your pump shut-off head plus any surge allowance, not merely your cut-out setting. Third is factory precharge, which almost always needs adjusting on site to sit just below your cut-in pressure. Fourth is the connection: size, thread standard, and whether the tank is vertical floor-standing or horizontal, since horizontal units change your plant room footprint and pipework routing. Fifth is wetted material and coating, on both the membrane and the shell interior, which decides whether the tank is suitable for potable service or a fire reserve loop. Send us your pump curve, controller cut-in and cut-out settings, required drawdown, potable or non-potable duty, and available plant room dimensions, and we return a specification against those figures. Where the application is a pressure vessel requiring ASME coverage, we confirm that on the quotation rather than assuming it.

Philippine plant room drawings mix units, so the first step is converting to one basis. One US gallon per minute equals 0.0631 litres per second, so a 100 GPM pump is 6.31 litres per second. One cubic metre per hour equals 0.278 litres per second, or 4.40 GPM. Our guide on GPM to LPS pump conversion for PH specifications has the full factor table. Fixture demand comes off the NSPC fixture unit method and is compared against the pump duty point, not the nameplate. Once you have a demand figure, tank sizing becomes a cycle rate question. Divide your usable drawdown by the net fill rate, which is pump output minus concurrent demand, to get pump run time per cycle. Divide the same drawdown by the standing demand to get pump-off time. Add the two for cycle length, and 3,600 divided by that figure is your starts per hour. If that number exceeds what your motor and starter tolerate, you either add tank volume, widen the pressure differential, or move to a variable speed set. On a VFD duplex control panel arrangement the tank is smaller in duty because the drive holds pressure rather than cycling, but it is not optional: it still absorbs the no-flow condition and prevents the drive from hunting at zero demand. Our guide on how to size a booster pump for a commercial building walks the same arithmetic against a worked example, and the VFD versus fixed speed pumps guide covers when the variable speed route pays.

Both types separate air from water, and both are sold under the loose label pressure tank, but the service implications differ. In a diaphragm tank the membrane is a sheet fixed across the vessel, dividing it into an air side and a water side. Construction is simpler, the unit is usually more compact for a given nominal volume, and on fixed-diaphragm designs the membrane is not field-replaceable, so end of membrane life means end of tank life. In a bladder tank the water is contained inside a bag suspended within the shell, so water never touches the vessel wall, and on most designs the bladder can be pulled and replaced through a flange while the vessel stays in place. That replaceability is the argument for bladder units on plant that will run for years under continuous duty. At the 200L decision point the choice is genuinely open, and it is usually decided by whether the plant room allows service clearance for bladder removal, whether the duty is potable, and whether the buyer is optimising first cost or ten-year cost. We quote both against the same duty so the comparison is on paper rather than assumed. For vessels above this range, our hydropneumatic bladder pressure tank range covers the larger options in the same series.

JOHOB Hardware Trading sources from Philippine and Chinese factories and delivers with local warranty and after-sales support, with the warranty terms stated on the quotation rather than implied. On the equipment we supply, certification coverage can include ISO 9001 on the manufacturer quality management system, TUV SUD testing, CE marking on electrical and material handling items, and ASME on pressure vessels where applicable. Coverage varies by item, so we identify which certificates apply to your specific tank and pump package on the quotation, and we do not claim certification that the supplied item does not carry. Pricing is quote-based and we do not publish prices, because the figure moves with capacity, membrane type, working pressure, and the pump and panel it is packaged with. On commercial terms, 12 percent VAT applies to VAT-registered buyers, and Zero-VAT treatment applies to PEZA and SBMA locators and to exporters, which is worth flagging on your RFQ so the quotation is issued correctly the first time. Standard lead times run 21 to 35 days ex-stock and 45 to 90 days for made-to-order configurations, and we confirm which band applies before you build it into a construction programme. We respond to RFQs within one business day.

We deliver nationwide: NCR, the rest of Luzon, Visayas and Mindanao, including PEZA, SBMA, and Clark locators. A pressure tank rarely arrives alone, so we quote it as part of a package where that is what the project needs. On the pump side we source established European brands including Grundfos, DAB, and Speroni, alongside CDL vertical multistage pumps, and we will put both options against the same duty point so the reliability and cost trade-off is visible rather than argued. One detail that catches out imported specifications: the Philippine grid runs at 60 Hz, while much European pump data is published at 50 Hz, so a curve read off a European catalogue without correction will misstate both head and flow. We correct for that before quoting a tank against it. Control side, we supply VFD duplex panels and other electrical panels built by Chutian using Inovance drives, which change how hard the tank has to work by holding pressure instead of cycling the motors. Valves and fittings for tank connections and stainless steel flexible hoses are supplied from the same order. After delivery, warranty and after-sales are handled locally rather than routed back to a factory abroad, which is the practical difference between buying a 200L diaphragm unit from a Philippine supplier and importing it direct.

• Hydropneumatic Bladder Pressure Tanks (Larger Capacities)
• Commercial Booster Pump Systems
• VFD Duplex Control Panels
• Guide: How to Size a Booster Pump for a Commercial Building
• Guide: VFD vs Fixed-Speed Pumps
• Valves and Fittings

Reviewed: July 2026