Product Overview

Spirax Sarco DCV3 and DCV3LT are disc-type flange wafer-mounted check valves, specifically designed for industrial applications, widely suitable for process pipelines, hot water systems, steam and condensate systems, while also supporting various media such as oil, air, and gases. The product connection dimensions comply with EN 558 part 1 series 49 standard, certified by ISO 9001, and meet European Equipment Directive 97/23/EC requirements, featuring both sealing performance and structural stability.

Core Configuration and Selection

Seat Material Selection

• Standard Configuration: Metal seat, suitable for steam systems
• Optional Configuration: Viton soft seat (suitable for oil, gas, air systems); EPDM soft seat (suitable for water systems)

Spring Configuration Selection

• Standard Spring: Austenitic stainless steel (BS 2056 316 S42), general purpose for normal conditions
• Heavy Duty Spring: Austenitic stainless steel (BS 2056 316 S42), opening pressure 700 mbar, suitable for boiler feed water applications (maximum port size DN65)
• High Temperature Spring: Nickel alloy (Nimonic 90), suitable for high temperature conditions
• No Spring Option: Suitable for low opening pressure requirements, must be installed vertically with flow direction from bottom to top

Tightness Class Selection

• Standard Configuration: Compliant with EN 12266 rate E standard
• Optional Configuration: Compliant with EN 12266 rate D standard (must be specified when ordering)
• Soft Seat Characteristic: Can achieve EN 12266 rate A standard when there is a certain pressure differential

Technical Parameter Details

Operating Range

• Maximum Operating Pressure (Metal Seat): 40 bar g @ 50°C; 33.3 bar g @ 300°C; 31.2 bar g @ 400°C (DCV3 only)
• Maximum Operating Temperature: 300°C (general); 400°C @ 31.2 bar g (DCV3 only)
• Temperature Limits: Viton seat -25°C~+205°C; EPDM seat -40°C~+120°C
• Special Note: Soft seat product operating range is limited by material, applications below minimum temperature require consultation with Spirax Sarco

Opening Pressure (No Flow Condition)

DN Port Size	Standard Spring/High Temperature Spring Opening Pressure (mbar)	No Spring Opening Pressure (mbar)	Heavy Duty Spring Opening Pressure (mbar)
15	25	20	700
20	25	20	700
25	25	20	700
32	27	20	700
40	28	20	700
50	29	20	700
65	30	20	700
80	31	20	-
100	33	20	-

Kv Value (Flow Coefficient)

DN Port Size	15	20	25	32	40	50	65
Kv Value	4.4	6.8	10.8	17	26	43	60

Flow Coefficient Conversion Formulas

• Imperial CV (UK): CV(UK) = Kv × 0.963
• US CV (US): CV(US) = Kv × 1.156

Dimensions and Weight (Approximate)

Port Size (DN)	Dimension A (mm)	Dimension B (mm)	Dimension C (mm)	Dimension D (mm)	Dimension E (mm)	Dimension F (mm)	Weight (kg)
15	60.0	43	38	16.0	29.0	15	0.13
20	69.5	53	45	19.0	35.7	20	0.19
25	80.5	63	55	22.0	44.0	25	0.32
32	90.5	75	68	28.0	54.5	32	0.55
40	101.0	85	79	31.5	65.5	40	0.74
50	115.0	95	93	40.0	77.0	50	1.25
65	142.0	115	113	46.0	97.5	65	1.87
80	154.0	133	128	50.0	111.5	80	2.42
100	184.0	154	148	60.0	130.0	100	3.81

Component Material Details

No.	Component Name	Material Specification	Standard
1	Body	Austenitic Stainless Steel	WS 1.4581
2	Disc	Austenitic Stainless Steel	ASTM A276 316
3	Spring Retainer	Austenitic Stainless Steel	BS 1449 316 S11
4	Standard Spring	Austenitic Stainless Steel	BS 2056 316 S42
5	Heavy Duty Spring	Austenitic Stainless Steel	BS 2056 316 S42
6	High Temperature Spring	Nickel Alloy	Nimonic 90

Installation and Maintenance

Installation Requirements

1. Install according to the flow direction arrow on the valve body. Check valves with springs can be installed in any orientation
2. Check valves without springs must be installed on vertical pipelines with flow direction from bottom to top
3. Rotate the valve body to contact the flange connection bolts, ensuring the valve is centered in the pipeline
4. Flanges, bolts, and nuts must be provided by the installer
5. Not suitable for applications with severe pulsation such as air compressors

Maintenance Instructions

• Product has no spare parts, maintenance should refer to the accompanying Installation and Maintenance Guide (IM-P134-08)
• Special low temperature testing requires additional charges, please consult Spirax Sarco for details

Pressure Loss Calculation

Basic Description

• Pressure loss chart is based on 20°C water tests, applicable to horizontally installed standard spring-loaded check valves
• Vertical flow conditions only show minor deviations at small openings, other fluids require calculation of equivalent water flow rate

Ordering Instructions

Ordering Code Meanings

Code	Configuration Description
N	High Temperature Spring + Standard Metal Disc
W	No Spring + Standard Metal Disc
H	Heavy Duty Spring + Standard Metal Disc
V	Standard Spring + Viton Soft Seal Disc
E	Standard Spring + EPDM Soft Seal Disc
WV	No Spring + Viton Soft Seal Disc
WE	No Spring + EPDM Soft Seal Disc
HV	Heavy Duty Spring + Viton Soft Seal Disc
HE	Heavy Duty Spring + EPDM Soft Seal Disc
T	Compliant with EN 12266 rate D standard (default without marking is rate E)

Ordering Example

Spirax Sarco DN50 DCV3 check valve, stainless steel material, installed between EN1092 PN25 flanges (must specify seat type, spring type, and tightness class standard)

Certificate Information

• Standard "Test Report" provided
• Optional EN 10204 3.1 material certificate (must be specified when ordering)

Safety Handling

• Fluorinated rubber (Viton) components may decompose to produce hydrofluoric acid when approaching 315°C and above
• Avoid skin contact and inhalation of hydrofluoric acid, as it can cause skin burns and respiratory damage
• Fluorinated rubber should be disposed of according to the recommended method in the Installation and Maintenance Guide. Proper disposal poses no environmental hazard