BASIC MAIN VALVE

All diaphragm control valves consist of a main valve and a pilot control system. The basic main valve is the series 879 (Model M900 for larger valve sizes).

Basic Main Valve - 3D cutaway view

Diaphragm control valve — main valve body, diaphragm, stem, disc and flow path

The basic main valve forms the core of all Punawa diaphragm-actuated control valves. Two body designs: FULL PORT (879/00) and REDUCED PORT (879/10). DN 50–300, pressure class 10 / 16 / 25; Model M900 for larger sizes.

Quick Specifications

  • ✓FULL PORT – 879/00
  • ✓REDUCED PORT – 879/10
  • ✓DN 50–300 (reduced bore)
  • ✓Pressure class 10 / 16 / 25

Model GF 900 — Main Valve Description

  • ✓Drip-tight, positive seating
  • ✓Service without removal from line
  • ✓Threaded, flanged or grooved ends
  • ✓Globe or angle pattern
  • ✓100% factory tested

The Model GF 900 is a hydraulically operated, diaphragm actuated, globe or angle pattern valve. It consists of three major components: body, diaphragm assembly, and bonnet. The diaphragm assembly is the only moving part and is guided top and bottom by a precision machined stem.

The valve utilizes a non-wicking diaphragm of nylon fabric bonded with synthetic rubber. A resilient synthetic rubber seal matched to the seat provides a drip-tight seal when pressure is applied above the diaphragm.

It is the valve of choice for system applications requiring remote control, pressure regulation, solenoid operation, rate-of-flow control, liquid level control or check valve operation. The rugged simplicity of design and packless construction assure a long life of dependable, trouble-free operation. It is available in various materials and in a full range of sizes, with threaded, flanged or grooved ends.

Connection Standard

  • ✓Flanged: ISO 7005-2 (ISO 10, 16 & 25)

Water Temperature

  • ✓0 – 80°C

Working Pressure

  • ✓ISO PN 16: 16 bar
  • ✓ISO PN 25: 25 bar

MATERIALS

Component materials and standards (Bill of Materials).

Basic Main Valve - Materials and standards specification table (Bill of Materials)

REDUCED BORE

Cross-sectional view of the main valve — components and assembly.

Basic Main Valve - Reduced bore cross-section technical drawing with numbered components

MANUFACTURING & MATERIALS

Manufacturing standards and component materials.

Manufacturing standards — EN 1074-1, EN 1074-5, EN 558 S1, EN 1092-2

MANUFACTURING

Valves for water supply, regulating valves, face to face, drilling flanges

Materials — Body, Cover, Obturator, Stem, Diaphragm, Bolts and standards

MATERIALS

Component materials and standards (Bill of Materials)

1. CORROSION PROTECTION

  • ✓COATED INSIDE-OUTSIDE
  • ✓COATED ACCORDING TO GSK

2. CERTIFICATES

  • ✓DM 174 (I)
  • ✓WRAS (UK)
  • ✓ACS (F)
  • ✓DVGW (DE) — COATING & RUBBERS

3. APPLICATIONS

WATER

4. TESTING

  • ✓EN 12266-1 (ISO 5208) — PRESSURE TESTS — GRADE “A”

DIMENSIONS REDUCED BORE

Face-to-face and front view dimensions; dimensional data table (EN 558 S1, EN 1092-2 PN10/PN16).

Reduced bore valve — face-to-face dimension L (side view)

Face-to-face dimension (L)

Reduced bore valve — front view dimensions A, H, Ød, ØK, ØD

Front view — A, H, Ød, ØK, ØD, nr × Øf

Dimensional data table — DN, L, H*, ØA, drilling flanges PN10/PN16, weight (kg)

EN 558 S1 — L, H*, ØA. Drilling flanges EN 1092-2 PN10 / PN16. Weight [kg]. Dimensions in mm.

DIAGRAMS

DIAGRAM FOR CAVITATION CONTROL

The diagram shows indicatively the two operating areas of the reducer, according to the applicable upstream and downstream pressures.

AREA A: continuous working conditions, no cavitation risk.

AREA B: intermitting working condition, possibility of cavitation.

Continuous working conditions in the B zone can damage the internal components more rapidly. Appropriate design precautions must be adopted if the valve works in this zone; consult technical support for detailed application guidance.

WORKING CONDITIONS LIMITS

  • ✓Recommended fluid velocity upstream of the valve: for continuous service: 3.5 m/s; for peak service: 5 m/s
  • ✓Minimal necessary differential pressure for the valve functioning: 0.2 bar
  • ✓Working temperature: max +80°C